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2002 Fruit and Vegetable Crops Research Report

VEGETABLES

Yields and Gross Returns from New Slicing Cucumber Varieties

Brent Rowell, April Satanek, Darrell Slone, and John C. Snyder, Department of Horticulture

Introduction

Slicing cucumbers have become a profitable "new" crop for a number of Kentucky growers. Growers planted more than 50 acres of slicing cucumbers this year for fresh market sales through new marketing cooperatives in Central and Western Kentucky. Slicing cucumber trials had not been conducted in Kentucky since 1989, and many new disease-resistant hybrids have come on the market since then. Some Kentucky growers have tried trellising cucumbers to achieve higher yields of more uniformly dark green fruit. Anecdotal evidence suggests that trellising improves color and lowers the incidence of "yellow bellies"; however, this has not been tested, and it is not known if an increase in yields of higher quality cucumbers would pay for the labor and material costs of trellising. Although the primary purpose of this trial was to compare new varieties, we also wished to observe differences between trellised and non-trellised cucumbers.

Methods and Materials

Sixteen slicing cucumber varieties were compared for yield, potential returns, and overall appearance in the spring of 2002 at the Horticultural Research Farm at Lexington. Dasher II and Marketmore 76 were included as standard (check) varieties. Marketmore 76 is an old standard for disease resistance, while Dasher II is one of the most popular hybrids in the region. With the exception of open-pollinated Marketmore 76, all varieties tested were gynoecious F1 hybrids with approximately 12% pollinators. All varieties are reported to have disease resistance although our trial was nearly disease-free and resistance was not evaluated in this trial.

Cucumbers were seeded in 72-cell flats in the greenhouse on 16 May and transplanted to the field after 12 days on 29 May. Most cultural practices were according to our current commercial recommendations for Kentucky. A total of 50 lb N/A was applied prior to transplanting; an additional 70 lb N/A from ammonium nitrate was fertigated in seven weekly doses of 10 lb N/A. All P and K were applied preplant according to recommendations based on soil tests. The fungicide Ridomil Gold was applied on 28 May and was followed by alternating weekly applications of Bravo or Quadris for disease control. The systemic insecticide Admire was applied as a post-transplant drench one day after transplanting for cucumber beetle/bacterial wilt control. A single application of Pounce and two applications of Sevin were made after 27 June for cucumber beetle control.

Plots consisted of raised beds 8 ft long with black plastic mulch and drip irrigation; bed centers were 6 ft apart. Single plants were spaced 12 inches apart within double rows (two rows/bed) with approximately 15 inches between double rows (16 plants/plot). Plots were replicated four times in a randomized complete block design. Cucumbers were harvested every three to four days from 1 July to 29 July for a total of nine harvests. After grading into either marketable fruit or culls, fruits were counted and weighed. Marketable fruits were sorted according to USDA grades U.S. Fancy, U.S. No. 1, U.S. No. 1 Large, U.S. No. 1 Small, and U.S. No. 2.

Yields, Gross, and Early Returns. Average yields of each USDA grade were compared using Waller-Duncan's LSD (k-ratio t-tests, P = 0.05) following an analysis of variance. Although yields for these grades are important, we believe that the large tables of data usually reported are confusing and often difficult to interpret. Although reporting only total marketable yields simplifies matters, this variable is of limited practical use to commercial growers and can mask more important economic considerations. It is possible that some varieties with high total marketable yields might have been later maturing with a larger proportion of their marketable yield achieving only marginal prices later in the season. Making planting decisions based on total marketable yield data alone could lead to disastrous results.

Because we believe comparing the potential income or gross returns per acre is a more useful way of evaluating yield data from several different grades, raw data were converted by multiplying the yield of each grade by that grade's actual price for that harvest date. Yields in pounds per acre were first converted to boxes per acre by dividing yield by the average weight of one 1¹/₉ bushel box of slicing cucumbers (55 lb). Box yields were multiplied by actual average weekly wholesale prices received by a Kentucky cooperative less box costs, packing charges, and commissions (Table 1). The resulting single variable "gross return" provides a better indicator of a variety's overall performance, taking into account yields of the different grades and their price differentials. "Early returns" were calculated in the same way using data from only the first three harvests on 1 July, 5 July, and 8 July.

Table 1. Average weekly wholesale prices received for slicing cucumbers during the trial harvest period from 1-29 July 2002. Prices are FOB less $1.40 box/packing charge and less 16% marketing commissions. Prices are dollars per standard 1 1/9 bu (55 lb) carton.
Week Ending		Market Gradez
		Super-select	Select	Small	24-Count
		price per box ($)
06 Jul		9.99	5.21	9.89	3.23
13 Jul		11.41	6.58	7.61	2.96
20 Jul		5.70	4.06	5.75	1.57
27 Jul		5.95	2.66	4.32	0
03 Aug		4.69	0.80	3.91	0.05
z	Market grades correspond to the following USDA grades: Superselect = U.S. Fancy + U.S. No. 1; Select = U.S. No. 2; Small = U.S. No. 1 Small; 24-count = U.S. No. 1 Large.

Trellising. In order to make preliminary observations on the possible benefits from trellising, the four blocks (replications) in this trial were treated as follows (all plots on raised beds with black plastic and drip irrigation):

• Block 1: no trellis.
• Block 2: simple trellis; tomato stakes were placed on each side of the beds every 4 ft of row (every four plants). Tomato twine was wrapped around each stake to create a "fence" on both sides of the bed. Cucumber plants were simply laid up upon this "fence" by hand and were not otherwise trained to the trellis (Figure 1). Four stringings were used to make trellises in all trellised blocks.
• Blocks 3 & 4: more complex trellis; stakes placed as in Block 2 but with strings that crossed over from one side of the bed to a stake on the opposite side, creating an "X" pattern. It was thought that this method might be better for training vines to the trellis (Figure 2).

Although this arrangement of trellising or not trellising blocks does not allow for statistical comparisons, it was intended to give us some indication of the possible benefits from trellising. In addition to this trial, several farmers' field demonstrations of trellising for slicing cucumbers were conducted in 2002, the results of which can be found elsewhere in this volume.

Figure 1. Simple trellising method used in Block 2 of slicing cucumber cultivar trial at Lexington, 2002.

Figure 2. Trellising method using crossed twine used in Blocks 3 and 4 of slicing cucumber cultivar trial at Lexington, 2002.

Fruit Appearance Ratings. All fruits of each trial entry harvested from all four replications were graded and laid out on the ground for careful examination and appearance ratings on 12 July. Fruits were visually assessed for shape, extent of yellow color, and overall appearance. Appearance ratings took into account, in order of importance, overall attractiveness, shape, shape uniformity, and color.

Results and Discussion

Yields and Returns. Varieties are ranked from highest to lowest yield of a combination grade of U.S. Fancy plus U.S. No. 1 fruits in Table 2. This combination corresponds to the trade designation Superselect. The U.S. No. 2 grade corresponds to the Select category, while fruits of the U.S. No. 1 Large grade are usually packed as 24 count (24 fruits/box). The group of highest yielding varieties included SRQ 2389, Dasher II, Daytona, Panther, Indy, and Thunder; these were not statistically different from SRQ 2983, which was the highest yielding entry (Table 2). All varieties in this group had 65% or more fruit graded as Superselect except for SRQ 2389 (59%). Other varieties with high average percentages of Superselect fruit included Stonewall, General Lee, Greensleeves, Intimidator, and Turbo.

Table 2. Marketable yields and gross returns of slicing cucumber varieties and advanced breeding lines; data are averages from four replications at Lexington, Kentucky, 2002. Entries ranked from highest to lowest yield of U.S. Fancy plus U.S. No. 1 grade fruits.
Entry		Seed Source	U.S. Fancy+ U.S. No. 1 (tons/acre)	Marketable YieldsZ			Gross Returnsy $/acre	Early Returns $/acre	Overall Appearancex
				% Fancy+ No. 1 (%)	U.S. No. 2 tons/acre	U.S. No. 1 Large tons/acre
SRQ 2983		SS	35.1	71	8.4	6.0	11555	4495	4.5
SRQ 2389		SS	33.8	59	13.7	9.6	12311	4153	4.5
Dasher II		S	31.1	75	5.4	5.1	9951	4086	5.0
Daytona		S	30.4	70	7.8	5.3	10392	4314	4.0
Panther		SS	30.4	65	6.1	10.1	9879	3737	5.7
Indy		S	30.1	71	5.9	6.7	9589	3855	5.7
Thunder		S	29.9	74	6.2	4.5	9922	4802	4.2
SRQ 2387		SS	28.6	62	10.2	7.6	10314	4053	4.0
Greensleeves		HM	28.6	70	7.7	4.5	9627	4012	5.0
Stonewall		HM	27.4	75	5.9	3.1	8699	3594	5.7
General Lee		HM	27.2	72	6.7	4.1	9079	3274	4.0
Speedway		S	26.8	63	7.7	8.6	9586	4641	5.5
Intimidator		S	26.1	67	8.3	4.4	9237	4126	3.7
Turbo		S	24.5	66	7.9	4.7	8162	2087	5.5
SliceMore		SK/SW	23.0	60	8.3	7.4	8447	3426	4.5
Marketmore 76		SW	20.0	64	5.4	5.8	6657	1470	5.0
Waller-Duncan LSD (P = 0.05)			5.8	6.3	2.5	3.7	1593	772	ns
z	The combined yields of USDA grades Fancy and U.S. No. 1 are equivalent to the Superselect marketing category, while U.S. No. 2 grade is equivalent to Select; yields of U.S. No. 1 Large are equivalent to yields of cucumbers used in 24-count packs.
y	Gross returns are calculated for each entry by multiplying yields of each marketing category (Superselect, Select, and 24-count) by its appropriate price for a given harvest date (9 harvests). Prices used were actual average weekly prices received by a Kentucky cooperative from July 1-30, 2002 less $1.40/box packing/box charge and less 16% commissions. Higher returns may reflect earlier yields and/or higher yields of Superselect cucumbers. Prices are shown in Table 1.
x	Appearance ratings: 1 = worst; 9 = best taking into account, in order of importance, shape, shape uniformity, and color.

Sunseed's SRQ 2983 and SRQ 2389 had significantly higher gross returns than the other varieties tested (Table 2). Other varieties with very high returns included Daytona, SRQ 2387, and Dasher II. Early returns were highest for Thunder, Speedway, SRQ 2983, and Daytona. While there were no statistically significant differences among the qualitative assessments shown in Table 3, average overall appearance scores tended to be higher for Panther, Indy, Stonewall, Speedway, and Turbo. Appearance scores tended to be lower for Intimidator, Daytona, SRQ 2387, and Thunder. SRQ 2389, SRQ 2387, SRQ 2983, Stonewall, Dasher II, Turbo, and Thunder, tended to have less fruit yellowing, while Marketmore 76 and Speedway appeared to have more fruit yellowing than the other varieties (Table 3). Intimidator tended to have more misshapen or curved fruits than the other varieties tested.

Table 3. Fruit shape, color, and overall appearance assessments for slicing cucumber varieties; scores are averages for all fruits of each variety from four replications harvested on 12 July 2002; varieties are listed from highest to lowest U.S. Fancy + U.S. No. 1 yields.
Entry		Shapez	Fruit Yellowingy	Appearance Ratingx
SRQ 2983		2.5	1.7	4.5
SRQ 2389		2.0	1.2	4.5
Dasher II		3.5	1.5	5.0
Daytona		2.7	2.0	4.0
Panther		3.0	2.2	5.7
Indy		3.5	2.2	5.7
Thunder		2.7	1.5	4.2
SRQ 2387		2.2	1.2	4.0
Greensleeves		3.0	1.7	5.0
Stonewall		3.0	1.2	5.7
General Lee		2.7	2.0	4.0
Speedway		3.2	2.7	5.5
Intimidator		2.7	2.0	3.7
Turbo		3.0	1.5	5.5
Slice More		2.7	2.0	4.5
Marketmore 76		3.5	3.0	5.0
Statistical significance (P = 0.05)		ns	ns	ns
z	Shape ratings: 1 = worst (large percentage of misshapen fruits) to 5 = best (most fruits uniform, long, straight, cylindrical).
y	Extent of yellowing: 1 = best (no yellow color on most fruits) to 5 = worst (large percentage of fruit surface yellow on most fruits).
x	Appearance ratings: 1 = worst; 9 = best taking into account, in order of importance, shape, shape uniformity, and color.

Trellising. Since each trellising method was applied uniformly to all varieties in a separate block or replication in the trial, it was impossible to make any conclusive statements regarding benefits of trellising based on these results. As we were well aware when planning the trial, the effects of trellising were confused ("confounded" is the proper statistical term) with the effects of field position (the location of a block and its trellising method in the trial field). Having said that, however, it is still useful to call attention to our observations, especially for characteristics like fruit color and appearance that are likely less affected by field position than by trellising. There was a highly significant difference among blocks/trellising methods for the extent of yellowing on fruits with the untrellised block showing the most yellowing (rating of 2.3 on a scale of 1 to 5 where 1 = best [no yellow color on most fruits] and 5 = worst [large percentage of fruit surface is yellow on most fruits]). Fruits from the simple trellis block showed the least yellowing (1.2 rating). While there were no other statistical differences among blocks/trellising methods for fruit quality ratings, the trend was for slightly better fruit appearance ratings with trellising than without trellising (data not shown). We also found no indication of improvement of fruit color or appearance with the more complex trellis versus the simpler trellis. We also noticed that cucumber beetle damage to fruits tended to be more serious in the trellised blocks where it was more difficult to achieve complete spray coverage. The question for further research is whether a small improvement in fruit appearance is worth the considerable added expense of trellising.

We recommend the following varieties for further on-station trials and for small test plantings in growers' fields: SRQ 2983, SRQ 2389, Panther, Greensleeves, and Stonewall. Dasher II, Daytona, Indy, and Speedway will remain in the list of suggested slicing cucumber varieties for Kentucky growers.

Acknowledgments

The authors would like to thank the following persons for their hard work and assistance in the successful completion of this trial: Dave Lowry, Larry Blanford, Phillip Bush, Barry Duncil, Justin Clark, Stephanie Goode, Courtney Bobrowski, Witoon Jaiphong, Sopon Issaravut, Takanobu Suzuki, Darren Taylor, Eric Bowman, and Spencer Helsabeck.

Trellising Slicing Cucumbers in Western Kentucky

Clint Hardy and Brent Rowell, Department of Horticulture

Introduction

Fresh market slicing cucumbers are being grown in Western Kentucky as a supplement to tobacco and other farm enterprises. Growers are interested in producing long, straight, dark green cucumbers that show very little yellowing. A combination of U.S. Fancy and U.S. No. 1 grades (i.e., "Superselect") receives the highest prices, and growers naturally want as much of their harvest to be in this category as possible. In this demonstration trial, we evaluated two different trellising methods to determine which, if any, produced more quality fruit, and if increased yields from either method would pay for the cost of trellising.

Materials and Methods

The variety chosen for the demonstration was Speedway, which performed well in 2001. The trial plots were located within a grower's field in McLean County. Besides trellising, the grower-cooperators kept the plots sprayed, maintained, and watered. Plants were started in 242-cell trays and transplanted to the field on 31 May using raised beds, black plastic mulch, and drip irrigation. The trial was set up as a randomized complete block design with four replications. Each plot contained 50 plants in 18-inch- wide double rows with 15 inches between plants within the rows. Phosphorus and potassium fertilizer was applied based on soil test results. One-half of the total of 100 lb N/A was applied prior to planting with the remainder applied weekly through drip irrigation at 10 lb N/A per application. No herbicides were used, and no insecticides were used until after the crop was established. Bravo fungicide was applied weekly according to current UK recommendations. Treatments were: 1) no trellis, 2) single-stranded trellis wrapped in five "layers" or stringings, and 3) a double-stranded trellis also in five stringings. Plots were scouted twice weekly to monitor pests and diseases. Plots were harvested 13 times between 24 June and 29 July.

Trellis Types. Stakes for the trellises were ordinary 52-inch long tobacco sticks that were driven 9 inches into the raised beds directly in the plant row. A stick was placed every five plants (about 6 ft apart). Since there were two rows per bed, there were also two rows of sticks on each bed. Two sticks were also driven every 25 plants on each row to serve as braces for the structure and to allow a gap to pass harvest buckets across. With the sticks in place, we began the stringing process. Staked tomato twine was used. The twine was wrapped around a stick once and then moved to the next stake. This was done at five different positions, beginning at 6 inches above the plastic and ending at the top of the stick. When finished, the trellis looked similar to a five-strand fence (Figure 1). The double-strand trellis type was exactly the same as the single, but two strings were used to see if the plant would be better supported when it held a full fruit load. The vines were manually trained twice prior to the first harvest in order to ensure the trellises were used to their full potential.

Figure 1. Trellised cucumber planting (single strands) in Daviess County, Kentucky, 2002.

New tobacco sticks cost $0.15 each; this cost can be amortized over two years resulting in an annual cost of $0.07/stick. Approximately 2,070 sticks are required per acre so stake costs would be around $145 per acre. The estimated labor cost for trellis establishment and removal was $400 per acre. Total material and labor costs for trellising cucumbers were about $600/acre.

Results and Discussion

Cucumbers from the same treatment but from different replications were inadvertently combined at harvest so that it was impossible to perform statistical analyses on the data collected; however, some general trends were observed. Yields of Superselect cucumbers were considerably higher for the trellised treatments (nine to 10 boxes/plot) than for non-trellised (six boxes/plot), while yields for most other grades were similar among the treatments (Table 1). More fruit was culled from the non-trellised plots than from trellised plots (Table 1). There appeared to be little difference between the single- and double-stranded trellises.

Table 1. Yields of market grades of ‘Speedway’ slicing cucumbers from trellised and non-trellised plots in McLean County, Kentucky, 2002. Data are combined yields from four replications of each treatment.
Market Grade	No Trellis	Single Strand	Double Strand
	boxes/plot
Superselect	6	9	10
Select	10.5	9	10.5
Large (24 per box)	7	8	6
Small	3	2	2.5
Culls	5.5	3.5	3
Avg. harvest time for 200 plants	16 min.	17 min.	18 min.

No time was saved in harvesting trellised versus non-trellised cucumbers. It was also observed that due to better exposure to sunlight, trellised cucumbers were more uniform in color than the non-trellised. Early summer was a good growing season this year, and cucumbers were little affected by disease. We observed that the trellised cucumbers could have been picked for about two weeks longer than those grown on the ground. When the non-trellised vines began to grow off the plastic and onto the bare ground middles, belly rot became a common problem in mature fruit; at the same time, trellised vines continued to produce good quality fruit with little belly rot.

Costs and Returns. When the small plot yields in Table 1 were extrapolated to yields on a per-acre basis, the yield of Superselect cucumbers was 1,780 boxes per acre for the trellised plots versus 1,125 boxes per acre for non-trellised. Based on an average return to the grower of $7.55 per box of Superselect cucumbers for the month of July, the 655 boxes per acre gained from the trellised plots would have been worth an additional $4,952/acre, returning more than eight times the cost of trellising.

Although this test needs to be repeated, we concluded that trellising did contribute to a better crop overall. Growers need to use this information with caution, however, as fewer benefits were observed from trellising in the cucumber variety trial at Lexington. In the Lexington trial, we also observed problems with spray coverage within the dense foliage of the trellised plantings and subsequently had more cucumber beetle feeding damage to fruits in those plots.

The grower-cooperators involved in this demonstration were happy with the results and plan to continue using the single-string trellis method, while another grower in the same county decided not to continue using trellises after having problems with spray coverage and damage from cucumber beetles. A few growers who tried trellising cucumbers in Central Kentucky this year reported that benefits were considerably greater in late summer plantings compared to spring plantings. Cucumber prices were moderate to high this year; had prices been lower, the extra material and labor costs of trellising may not have been justified.

Yield of Double-Cropped Cucumber Varieties for Fall Harvest in Western Kentucky

Clint Hardy, Brent Rowell, and John C. Snyder, Department of Horticulture

Introduction

Fresh market slicing cucumbers are becoming a major commercial vegetable crop in Western Kentucky. Cucumber production has increased in this area due to the strong marketing potential established through the West Kentucky Grower Cooperative. Since cucumber prices often rise in September and October, we wanted to evaluate nine different varieties in a late-summer planting. In addition, the trial was planted as a double crop after main season cucumbers to observe the feasibility of this technique.

Materials and Methods

Nine cucumber varieties were direct seeded on 7 August into old planting holes after plants from the previous crop had been removed. Glyphosate had been applied to burn down weeds and residues of the previous crop. The trial was conducted in a commercial grower's field near the co-op's packing facilities in western Daviess County. Drip tape from the previous crop was left in place and water was provided immediately after seeding in order to promote germination.

Black plastic mulch from the previous crop was painted white with a product called KoolGro®. KoolGro is formulated for use with plasticulture and is supposed to keep the area around the plants cooler than with unpainted black plastic. The trial was established as a randomized complete block design with four replications. Cucumbers were planted in double rows that were 18 inches apart with plants spaced 12 inches apart within the rows. Two seeds were sown in each planting hole; seedlings were later thinned so that 16 plants remained in each plot.

The plots had been fertilized prior to planting the previous crop. In addition, 10 lb N/A was fertigated weekly during the growing season. The crop was cultivated twice for weed control. Insecticides were applied as needed according to UK recommendations. Bravo was applied weekly, and Nova was applied twice for disease control. Ridomil Bravo was applied once. The plot was scouted once a week to monitor pests and diseases.

Results

Fungicide treatments were applied according to current recommendations; however, the cool and very rainy period that began in mid-September and continued through October resulted in serious plant and fruit losses from Phytophthora capsici that effectively ended the trial. This disease was prevalent in the portion of the grower's field where the trial was located after heavy rains occurred and standing water was observed. Ridomil Bravo was applied on 4 October and slowed subsequent development of the disease; however, severe fruit and plant losses had already occurred. This problem decreased quality and yield from the affected area in the trial field and resulted in much uncontrolled variability in the yield data collected. In addition, only four harvests were possible and yields were low (Table 1). Under these conditions, it was impossible to identify the best varieties with any confidence, and there were no statistically significant differences among varieties for most of the yield components measured (Table 1). We were also not able to detect any visible differences between the cucumbers in this trial on the white painted mulch and those in adjacent sections of the field that were grown on black plastic.

Table 1. Yields of fall-harvested, double-cropped cucumber varieties in Daviess County, Kentucky, 2002. Data are averages from four replications.
Variety		Seed Source	U.S. Fancy + U.S. No. 1z	Total Mkt.y
			boxes/acre
Speedway		S	179	523
SRQ 2387		SS	171	476
Indy		S	164	330
Daytona		S	161	290
SRQ 2983		SS	136	267
EX4675898		S	131	425
Greensleeves		HM	115	206
Turbo		S	114	209
SRQ 2389		SS	105	397
Significance			NS	NS
z	The combined yields of USDA grades Fancy and U.S. No. 1 are equivalent to the Superselect marketing category; yield expressed as number of 1 1/9 bu (55 lb) boxes/acre.
y	Total marketable yield includes combined yields of U.S. Fancy, U.S. No. 1, U.S. No. 2, U.S. No. 1 Large, and U.S. No. 1 Small.

While double cropping on black plastic helps spread out the annual expense of plastic mulch, drip tape, and labor required for laying and removal, the labor costs for direct seeding by hand were high. In addition, the increased risk of serious disease problems in double-cropped cucurbits should be weighed carefully when considering this planting technique. We plan to repeat this trial for fall-harvested cucumbers in 2003.

Yield and Powdery Mildew Resistance of Fall-Harvested Summer Squash

Brent Rowell, William Nesmith, April Satanek, Darrell Slone, Janet Pfeiffer and John C. Snyder, Departments of Horticulture and Plant Pathology

Introduction

Although squash from late summer plantings often achieve the highest market prices, fungal and virus diseases frequently cause serious damage in fall-harvested squash and are considered important barriers to profitable production in Kentucky and surrounding states.

Mixed virus infections commonly occur in fall-harvested summer squash in Kentucky. Watermelon mosaic virus (WMV, formerly WMV-2), zucchini yellow mosaic virus (ZYMV), squash mosaic virus (SqMV), cucumber mosaic virus (CMV), and papaya ringspot virus (PRSV, formerly WMV-1) have all occurred in Kentucky at one time or another and in most other southeastern states. Although the dominant virus(es) varies from site to site and from year to year, WMV has been the most frequently detected virus in summer squash (present in more than 90% of samples tested) during the last 11 years in Kentucky. Virus epidemics are often severe in late summer plantings and total destruction of the crop is not uncommon.

Effective virus resistance and tolerance were found among new transgenic (GMO) and conventionally bred cultivars tested in a fall-harvested trial in 1997 in Kentucky (see 1996-97 Kentucky Vegetable Crop Research Report). Although transgenic cultivars have become more popular with some growers since then, most yellow straightneck squash growers in Kentucky depend on cultivars with the precocious yellow (Py) gene for late-season production. These cultivars mask the greening effect in summer squash fruits when plants are infected by CMV or WMV but not if plants are infected by PRSV or ZYMV. In some areas, precocious yellow squash have reportedly been more difficult to market because of buyer preference for green, rather than yellow, fruit peduncles found in cultivars with the Py gene. Kentucky growers and marketers have not had difficulty marketing squash with this trait. Production of yellow crookneck squash, grown primarily in the southern part of Kentucky for southern markets, has been very risky without disease-resistant cultivars.

It was our intention to evaluate cultivars and breeding lines for yield and virus resistance in a fall-harvested trial. Because there was a near absence of virus diseases this year, cultivars and breeding lines were evaluated for marketable yield, powdery mildew (PM) resistance, and fruit appearance.

Materials and Methods

Thirty-four summer squash cultivars or advanced breeding lines (16 zucchini, nine yellow straightneck, and nine yellow semi-crookneck or crookneck entries) were evaluated at the University of Kentucky Horticultural Research Farm in Lexington in the late summer and fall of 2002. These included several of the best performing cultivars from the 1997 trial. Most cultural practices were according to our current commercial recommendations for Kentucky. Seeds were sown in the greenhouse on 18 July in 72-cell plastic trays and transplanted to the field on 6 Aug. Each plot consisted of eight plants spaced 18 inches apart in a single row on 6-inch high raised beds with white-on-black plastic mulch and drip irrigation. Beds were 6 ft apart from center to center. All 34 entries were planted together in a randomized complete block design with four replications. Cultivars of each type (zucchinis, yellow straightneck, or yellow crookneck) were grouped together within each block. Blocks consisted of two long rows with 16 or 17 entries per row. Single rows of the disease-susceptible cultivar Dixie were planted on both sides of each block to enhance natural disease buildup and uniform spread throughout the trial.

Sixty-five pounds N/A were applied prior to planting, while an additional 18 lb N/A were applied in three fertigations for a season total of 83 lb N/A. All P and K were applied preplant according to recommendations based on soil tests. Quadris was applied on Aug. 7, 14, and 30 for fungal disease control; a tank mix of Nova and Bravo was applied on Sept. 9 and 26. The systemic insecticide Admire was applied two days after transplanting as a post-transplant drench for cucumber beetle control. Two subsequent applications of Pounce were made for later season cucumber beetle and squash vine borer control.

Plots were harvested three days per week (MWF) from 27 Aug. until 4 Oct. for a total of 16 harvests. Fruits were counted and weighed after grading into either marketable fruit or culls. Marketable yield was expressed in terms of the number of half-bushel boxes per acre by dividing the total weight of marketable fruit per acre by 21 lb. Following an analysis of variance, average yields and disease ratings were compared using Waller-Duncan's K-ratio Ttest (P = 0.05).

Fruit Quality Ratings. All fruits of each trial entry harvested from all four replications were graded and laid out on tables for careful examination and quality rating on 11 and 20 Sept. Fruits were assessed for type, color, and overall appearance. Yellow squash type (straightneck, semi-crookneck, or crookneck) was determined based on our own observations rather than seed company descriptions. Yellow squash color was rated on a 1 to 5 scale with 1 = pale yellow with greenish tint and 5 = bright golden yellow. Zucchini squash color was scored from 1 = light green to 5 = very dark green, nearly black. Appearance was rated on a 1 to 9 scale with 1 = worst and 9 = best taking into account, in order of importance: overall attractiveness, shape, uniformity of shape, and color.

Disease Assessments. Plants were visually assessed for the extent of PM symptoms on leaves (both upper and lower surfaces) and stems on 11 Sept. and 7 Oct. Although we did not identify PM species in this trial, mixtures of Sphaerotheca fuliginea and Erysiphe cichoracearum are usually found in late-summer squash plantings; both species were identified in the 1997 trial.

Results and Discussion

This harvest season was exceptional in that only a few of the more than 2,000 plants in the trial field showed any virus symptoms or yielded unmarketable fruits having virus symptoms. This was in spite of the presence of other cucurbit trials, which were planted earlier at the same location, and in spite of the extensive planting of a susceptible cultivar within the trial field. Commercial squash growers in Central and Western Kentucky also reported very low virus incidence in 2002. Midsummer drought led to a decline in clover and other host plants, and this may have resulted in the low virus incidence.

Yellow Straightnecks. As was the case in 1997, conventionally bred hybrids having the precocious yellow gene were in the highest yielding group of yellow straightneck squash cultivars: Sunray, Multipik, Fortune, and Monet were not significantly different from the highest yielding Precious II (Table 1). Multipik and Fortune were also in this highest yielding group in 1997 when virus incidence was high. While lower yielding, Cougar and Seneca Supreme had the best fruit appearance scores among straightnecks (Table 1).

Table 1. Yields and powdery mildew assessments for yellow straightneck, crookneck, and zucchini squash cultivars, breeding lines; data are averages of four replications; appearance ratings are averages from two assessments of all fruits harvested from four replications.
Entry		Source	Typez	Mkt. Yield boxes/acrey	Powdery Mildewx			Appearance Ratingw
					11 Sept.	7 Oct.	Avg.
I. Yellow straightneck and slight semi-crookneck:
Precious II		AC	SN-Py	1660	1.8	0.7	1.2	5.5
Sunray		S	SN/sCN-Py	1536	0.1	0.4	0.3	6.5
Multipik		HM	SN-Py	1526	3.0	3.7	3.4	6.5
Fortune		RG	SN-Py	1513	3.7	3.2	3.5	6.5
Monet		HM	SN-Py	1511	2.5	3.5	3.0	6.5
Goldbar		S	SN	1475	2.5	2.7	2.6	5.5
Cougar		HM	SN/sCN-Py	1369	2.6	2.7	2.7	7.0
Seneca Supreme		S	SN-Py	1327	2.6	2.7	2.7	7.0
Lioness		HM	SN	1281	2.7	1.0	1.9	5.0
Conqueror III		S	SN,Tg-3+	1262	2.6	2.5	2.6	4.5
Liberator III		S	SN,Tg-3	1219	3.0	3.2	3.1	4.0
II. Yellow semi-crookneck or crookneck:
Medallion		AC	sCN/CN	1663	3.2	3.0	3.1	5.5
Sunglo		RG	sCN/CN	1495	0.2	0.5	0.4	5.5
Prelude II		S	CN	1462	0.0	0.1	0.1	5.5
Gentry		RG	sCN	1450	2.6	3.5	3.1	5.5
Dixie		S	CN	1384	3.9	3.5	3.7	5.5
Destiny III		S	sCN/CN,Tg-3	1267	3.5	3.5	3.5	6.0
Pic-n-Pic		SW	CN	1101	3.7	3.7	3.7	6.0
Waller-Duncan LSD (all yellow squash, P = 0.05).				220	0.6	0.7	0.6	---
III. Zucchini:
HMX 710		HM	Z	1722	0.0	0.0	0.0	7.0
Zucchini Elite		HM	Z	1694	3.3	2.3	2.8	6.0
SVT 4620327		S	Z, Tg-3	1686	0.4	0.0	0.2	5.5
Cashflow		RG	Z	1635	4.2	4.2	4.2	6.5
Lynx		HM	Z	1567	4.0	2.7	3.4	5.0
Dividend		RG	Z	1517	3.5	3.0	3.2	6.0
Spineless Beauty		RG	Z	1466	4.0	3.0	3.5	5.5
9523		SS	Z	1445	4.3	4.3	4.3	6.5
Revenue		RG	Z	1276	3.5	3.5	3.5	5.5
Robuster		SS	Z	1262	4.0	4.4	4.2	5.5
Senator		S	Z	1215	3.2	2.2	2.7	6.0
AXC 34		AC	Z	1207	4.7	3.5	4.1	6.0
Tigress		HM	Z	1172	2.0	1.7	1.8	6.5
Independence II		S	Z,Tg-2	1146	4.0	2.5	3.2	5.0
Seasons		AC	Z	1130	4.5	4.0	4.2	5.0
ACX 45		AC	Z	1123	5.0	4.2	4.6	5.5
Waller-Duncan LSD (zucchinis, P = 0.05)				326	0.6	1.3	0.7	--
z	All entries from conventional breeding programs except for: Tg = transgenic for resistance to two (Tg-2) or three (Tg-3) viruses; Tg-3+ = transgenic for three viruses with resistance to the fourth (PRSV) obtained through conventional breeding. Type descriptions based on our observations on 11 and 20 Sept.: SN = straightneck, CN = crookneck, sCN = semi-crookneck; some cultivars that we considered semi-crookneck are considered straightneck by the seed company and are included in the straightneck grouping; Py = has precocious yellow gene to mask virus symptoms.
y	Number of half-bushel (21lb) boxes per acre.
x	Visual rating scale: 0 = no symptoms, 5 = extensive symptoms on entire plants. Ratings took into account the percentage of upper and lower leaf and stem surfaces that were covered by powdery mildew symptoms; assessed by W. Nesmith on 11 Sept and 7 Oct (3 days after final harvest).
w	Appearance ratings: 1 = worst, 9 = best, taking into account, in order of importance, overall attractiveness, shape, and color.

Powdery mildew symptoms were first observed inside leaf canopies of some cultivars in mid-September. Sunray exhibited exceptional PM resistance, while Precious II also had PM resistance that was significantly better than the resistance of other cultivars in this group; Fortune and Multipik appeared to be the most susceptible to PM among the straightnecks tested (Table 1). In the absence of virus diseases, transgenic cultivars Conqueror III and Liberator III were the lowest yielding in the group and were susceptible to PM; these cultivars also had the lowest appearance scores (Table 1). Transgenics were among the highest yielders in 1997 when virus pressure was very high.

Yellow Crooknecks. While transgenic cultivars Prelude II and Destiny III were clearly superior among yellow crookneck entries in 1997 under intense virus pressure, only Prelude II was among the highest yielding crookneck cultivars in 2002. Conventionally bred cultivars Sunglo and Gentry were also not significantly different in yields from the highest yielding Medallion among crooknecks (Table 1). Both Sunglo and Prelude II showed an exceptional degree of PM resistance, while the other cultivars in this group were much more susceptible (Table 1). Lower yielding Destiny III and Pic-N-Pic had the best appearance scores, while appearance scores for the other cultivars in this group were deemed acceptable (Table 2).

Table 2. Fruit color, appearance, and other observations for yellow straightneck, crookneck, and zucchini squash cultivars and breeding lines; ratings are averages from two assessments (11 and 20 Sept 2002); all fruits bulked from four replications at each of the two harvests.
Entry		Typez	Colory	Appearance Ratingx	Shape/Comments/Suitability
Precious II		SN-Py	2.7	5.5	Very long with long, thick neck; pale yellow w/greenish tint at blossom end; 50% curved.
Sunray		SN/sCN-PY	3.0	6.5	Elongated teardrop shape; very slight crook; good color.
Multipik		SN-Py	3.2	6.5	Long teardrop shape.
Fortune		SN-Py	3.0	6.5	Medium long teardrop shape; 20% curved.
Monet		SN-Py	3.5	6.5	Teardrop shape; nice color.
Goldbar		SN	2.0	5.5	Long w/very slight crook in most; greenish cast.
Cougar		SN/sCN-Py	3.0	7.0	Long teardrop shape; slight crook.
Seneca Supreme		SN-Py	3.0	7.0	Teardrop shape; attractive.
Lioness		SN	1.5	5.0	Long w/slight crooks; greenish cast in smallest fruits.
Conqueror III		SN	1.5	4.5	Very long, thin; 50% slightly curved; greenish cast.
Liberator III		SN	1.5	4.0	Very long, thin; 50% slightly curved; greenish cast.
Medallion		sCN/CN	3.5	5.5	Good color; medium thick neck.
Sunglo		sCN/CN	2.0	5.5	Medium thick neck; pale w/greenish cast.
Prelude II		CN	2.0	5.5	Medium thick neck; greenish cast.
Gentry		sCN	3.5	5.5	Medium thick neck; shape somewhat variable.
Dixie		CN	2.0	5.5	Thick neck; greenish cast.
Destiny III		sCN/CN	2.0	6.0	Medium thick neck; greenish cast.
Pic-N-Pic		CN	2.7	6.0	Thinner neck than most; greenish cast in smallest fruits.
HMX 0710		Z	3.0	7.0	Medium dark green; 50% w/slight curve and very slight taper (almost cylindrical.
Zucchini Elite		Z	3.0	6.0	Medium green; 50% w/slight curve; larger diam. Blossom end (slight taper).
SVT 04620327		Z	3.7	5.5	Medium dark green; 50% w/slight curve; many w/slight and occasionally uneven taper.
Cashflow		Z	3.0	6.5	Medium green; 40% w/slight curve; very slight taper.
Lynx		Z	3.7	5.0	Medium green; 60% w/slight to moderate curve; slight taper.
Dividend		Z	3.0	6.0	Light to medium green; 20% w/slight curve; slight taper, nearly perfectly cylindrical; very nice looking.
Spineless Beauty		Z	3.7	5.5	Medium dark green; angular fruit; mostly slightly curved and tapered (larger blossom end).
9523		Z	4.0	6.5	Medium dark green; most slightly curved; strong taper (larger blossom end); attractive glossy color.
Revenue		Z	3.0	5.5	Light to medium green; slightly larger blossom end; most slightly curved.
Robuster		Z	3.0	5.5	Medium green; 20% curved w/very slight taper.
Senator		Z	2.5	6.0	Light to medium green; heavily speckled; most slightly curved with smooth taper; one plant with off-type fruits in this trial.
AXC 34		Z	3.0	6.0	Light to medium green; mostly slightly curved w/very slight taper.
Tigress		Z	2.0	6.5	Gray-green speckled; 50% slightly curved; tapered; one plant with off-type fruits in this trial.
Independence II		Z	2.7	5.0	Medium green; most fruits slightly curved and tapered.
Seasons		Z	4.2	5.0	Medium dark green; 40-50% slightly curved, straight to very slight taper; shape not uniform.
ACX 45		Z	4.7	5.5	Very dark green; most slightly curved; no taper.
z	Type descriptions based on our observations on 11 and 20 Sept. (SN = straightneck, SN-Py = straightneck with precocious yellow gene, CN = crookneck, sCN = semi-crookneck); some cultivars that we considered semi-crookneck may be considered straightneck by the seed company.
y	Color ratings for yellow squash: 1 = pale yellow with greenish tint; 5 = bright golden yellow; for zucchini, 1 = lightest green; 5 = nearly black.
x	Appearance ratings: 1 = worst; 9 = best, taking into account, in order of importance, overall attractiveness, shape, and color.

Zucchinis. One transgenic and six conventionally bred zucchini cultivars were in the highest yielding group that were not significantly different from highest yielding line HMX 0710; these included Zucchini Elite, SVT 04620327 (transgenic virus resistance), Cashflow, Lynx, Dividend, Spineless Beauty, and Sunseeds 9523 (Table 1). Dividend was also in the highest yielding group in 1997. As in 1997, the transgenic virus-resistant Independence II was among the lowest yielding zucchini cultivars. Appearance ratings were highest for HMX 0710, Cashflow, Sunseeds 9523, and Tigress; fruit from a single observation plot of Tigress also had high appearance ratings in 1997. Plots of both Tigress and Senator, however, had a single plant (of the 32 plants of each cultivar that were grown for the trial) that yielded off-type fruits. Zucchini Elite, Dividend, Senator, and ACX 34 also had good appearance ratings (Tables 1 and 2); Zucchini Elite, Dividend, and Senator had high scores in the 1997 trial.

PM resistance was exceptionally high in breeding lines HMX 0710 (no symptoms) and SVT 04620327; Tigress also appeared to be resistant or tolerant to PM. PM ratings were significantly lower for HMX 0710, SVT 04620327, and Tigress than for the other zucchini cultivars. Neither of the two numbered breeding lines had been named/released at the time of this writing.

Results from the 1997 fall-harvested trial at this location together with those from similar trials in other states demonstrated that transgenic virus-resistant squash cultivars could provide excellent resistance to two or more of the viruses involved in mixed infections in the southeastern United States. Transgenic zucchini line SVT 04620327 and transgenic crookneck Prelude II both have high levels of PM resistance and performed well in this trial; the other transgenic cultivars did not perform as well in 2002 in the absence of significant virus pressure and under epidemic powdery mildew conditions.

Marketable yields in late plantings can be expected to vary considerably among cultivars from year to year and location to location depending on the resistance package in the cultivar, diseases present in the field, and the growth stage at which the crop becomes infected. Precocious yellow straightneck cultivars remain an excellent choice for high yields and masking of green fruit symptoms associated with moderate epidemics of WMV and CMV. New straightneck cultivars Precious II, Sunray, Monet, and Cougar are recommended for small-scale trial by growers; Sunray and Precious II should provide valuable levels of PM resistance. Fortune and Multipik will remain on our list of suggested cultivars for Kentucky growers in spite of their susceptibility to PM. While lower yielding in this trial, transgenic virus resistant cultivars should perform considerably better in most late-summer plantings when virus diseases are serious risks for growers.

New crookneck cultivars Medallion and Sunglo are recommended for grower trial. Prelude II will remain the only transgenic crookneck on our list of suggested cultivars. New standouts among zucchinis recommended for grower trial are HMX 0710 (not yet released) for its high yields of attractive fruits and exceptional PM resistance. Cashflow, SVT 04620327 (not released), Lynx, and Sunseeds 9523 are also recommended for growers' trials. High levels of PM resistance are now available in cultivars of all three types of summer squash grown in Kentucky. PM resistance should be considered together with virus resistance, fruit appearance, and other horticultural characteristics in selecting cultivars for late-summer production.

Pumpkin Cultivar Trial, Eastern Kentucky

Terry Jones, Department of Horticulture

Introduction

As a fall crop, pumpkins allow Kentucky growers to extend their marketing season and take advantage of labor used to cut and house tobacco. Both wholesale and direct market pumpkin acreage has increased dramatically during the past five years. Howden has been the predominate cultivar grown for jack-o'-lantern sale. However, problems with fruit set during high temperatures and Fusarium fruit rot have created a need for better cultivars.

A pumpkin cultivar trial was conducted at the University of Kentucky Robinson Station, Quicksand, Kentucky. Ten cultivars, two of which were small or miniature pumpkins, were evaluated in replicated plots.

Methods

Seeds were planted directly in the field on June 18, 2002. Each cultivar was replicated four times in a randomized complete block design. Each replication consisted of a single row 20 ft long containing 10 plants (two/hill). Seeds were hand-sown 4 ft apart in the row with 14 ft between rows. The seed was planted about 1 inch deep. A total of 500 lb of 5-20-20/A was applied preplant. Fifty pounds per acre of N (ammonium nitrate) was applied as a sidedressing two weeks after planting. A second sidedressing of ammonia nitrate was applied when the vines began to run, bringing the total nitrogen applied to 125 lb actual N/A. Command 4EC (1 pt/A) was applied preplant and incorporated. Curbit 3EC at 2 qt/A was applied immediately after planting. Pest control sprays were applied during the growing season for disease and insect problems as conditions warranted. Overhead irrigation was applied as needed. Growing conditions during the season were hot and dry.

Results and Discussion

Pumpkin yields were very good for a hot, dry year (Table 1). None of the eight standard pumpkin cultivars showed any significant difference in fruit number. Appalachian, Gold Standard, Magic Lantern, and Pro Gold 510 all had more than 3,000 fruit per acre. Autumn King, Jumpin Jack, Gold Strike, and Gold Gem had closer to 2,000 fruit per acre. The highest yielding (lb/A) large jack-o'-lantern in the trial was Appalachian. Magic Lantern and Pro Gold 510 also produced well. Gold Gem produced the fewest pounds per acre and had the fewest fruit per acre. Pro Gold 510 had the largest fruit size. Touch of Autumn produced significantly more fruit and pounds per acre than Baby Bear. Both were attractive, nicely shaped miniature pumpkins. Appalachian, the best producing jack- o'-lantern in this trial, produces fruit on bush vines, which would allow for a much closer row spacing than that used in this trial. Gold Standard, a slightly smaller pumpkin, has consistently produced good yields of attractive fruit that are a nice size for school children. Magic Lantern, because of its resistance to powdery mildew, has potential for growers who follow a reduced spray program or do not own a good, high-pressure sprayer.

Table 1. Seed source, fruit number per acre, yield, average weight, and quality evaluations for pumpkin cultivars, Quicksand, 2002.
Cultivar		Seed Source	Fruit No./A1	Yield (lb/A) 1	Avg. Wt. (lb)1	Shape2	Smooth3	Ribbing4	Color5	Stem Quality6	Stem Color7
Touch of Autumn (RWS-6260)		RG	8,517 A	16,510 DE	1.9 D	3	4	3	LO	3	DG
Baby Bear		RU	6,145 B	7,106 E	1.2 D	3	4	3	MO	2	DG-T
Appalachian		PS	3,461 C	52,440 A	14.9 AB	1.8	2.8	2.3	DO	2.3	L-DG
Gold Standard		RU	3,306 C	36,250 BC	11.1 C	2.8	2.5	2.3	DO	3	MG
Magic Lantern		HM	3,228 C	42,580 AB	13.1 ABC	3	4.3	1.5	MO	2.5	MG
Pro Gold 510		RU	3,034 C	43,710 AB	15 A	1.5	3.5	4.3	LO	2	MG
Autumn King		RG	2,411 C	30,820 BC	12.7 BC	1.8	3	2.5	MO	2.5	DG-T
Jumpin Jack		RU	2,334 C	29,910 BCD	12.9 ABC	1.8	3	3.3	LO	1.5	T
Gold Strike		RU	2,061 C	30,750 BCD	14.2 AB	1.5	1.8	1.5	DO	1.8	DG-T
Gold Gem (Rex 38041)		RU	1,945 C	26,550 CD	13.8 AB	2.8	2.3	1.8	M-DO	1.8	T
LSD 8			1,543	14,300	2.2
1	Means followed by the same letter are not significantly different as determined by LSD (P = 0.05%).
2	1 = oblate or flat, 2 = blocky, 3 = round.
3	1 = rough, warty skin, 5 = very smooth.
4	1 = heavy ribbed, 5 = no ribbing, smooth.
5	lo = light orange, mo = medium orange, do = dark orange, ro = reddish orange, w = white.
6	1 = weak, small, breaks off; 3 = strong and large.
7	lg = light green, mg = medium green, dg = dark green, t = tan.
8	Least Significant Difference (P = 0.05).

Yield of New Muskmelon Cultivars in Eastern Kentucky

William Turner, Charles Back, and R. Terry Jones, Department of Horticulture

Introduction

Eastern cantaloupe has been identified as one of several profitable crops that Kentucky farmers can produce. Potential yields of 8,000 to10,000 fruit per acre, with gross returns of $5,000/A are possible. Variable costs are roughly $1,000 per acre, and net returns to the grower are in the $2,200 range. One farm cooperative, several grower marketing associations, and numerous farmers' market producers are currently producing cantaloupes for fresh market sales. This cultivar trial compares Athena, which is currently produced on 75% of all Eastern cantaloupe acreage, with five other cultivars that produce similar fruit. Six cantaloupe cultivars were compared to determine yield and size and for potential use by Kentucky growers for wholesale, roadside, and farmers' markets.

Materials and Methods

Cantaloupe seeds were planted in plug trays and grown in the greenhouse for four weeks before transplanting through black plastic on 28 May 2002. Cultivars were planted in a randomized complete block. There were four replications with five plants per replication. Each replication was 15 ft long with plants set 3 ft apart in the row. Rows were 7 ft on center.

A total of 150 pounds of nitrogen was applied through drip lines as either ammonium or potassium nitrate. Curbit 3E (1 qt/A) and Gramoxone Extra (2pt/A) were applied for weed control between the mulched beds one week after transplanting. An additional spot spray was made 14 days later to improve control. Admire 2F at the rate of 24 fl oz/A was applied as a drench just after transplanting, using a backpack sprayer with the nozzle removed. Either mancozeb or chlorothalonil was applied weekly, and Quadris was applied on alternate weeks during July and August. Endosulfan 3EC or Pounce 3.2EC was applied for insect control when needed.

Following harvest, cantaloupes were sold through a local produce stand. The owner observed customer reactions to the various melons and reported buyer preferences and comments when he came to obtain more melons. He also began selecting only those melons that his customers wanted.

Results

There were no significant differences in fruit number per acre for the six cultivars (Table 1). The average fruit weight of Athena was less than those of the other five cultivars. Odyssey, the highest yielding cultivar in the trial, produced significantly more cwt/A than Athena. The yields of the other four cultivars were not different from that of Odyssey or Athena. The appearance of Odyssey was very similar to that of Athena, except it was larger. Vienna fruit were not as attractive as those of the other cultivars and tended to have more cracking around the stem end. All six muskmelon cultivars produced marketable fruit. At a roadside market Minerva, Eclipse, and RML 8793VP were the first to sell. These are large, attractive melons that look like the Indiana melon that consumers wanted. Unfortunately, they are softer and do not store or ship as well as Athena. Athena and Odyssey also sold well as long as they had good size (larger than 5 lb). Vienna sold only if nothing else was available. None of the new cultivars tested is likely to replace Athena in the commercial wholesale market because produce buyers demand that particular melon. Odyssey might be mixed with Athena to improve overall fruit size.

Table 1. Maturity, seed source, average fruit weight, number of fruit per acre, yield, and shape and appearance evaluations for six muskmelon cultivars, Quicksand, 2002.
Cultivar		Days to Maturity*	Seed Source	Avg. Wt. (lb/fruit)1	Marketable Fruit/A1	Yield (cwt/A)1	Comments (Shape and Appearance)
Eclipse		63	SW	8.1 A	5906 A	480 AB	large size, good taste and quality, local sales
Odyssey		65	SU	8.2 A	6327 A	519 A	heavy netted, shallow sutures, holds & ships well
Vienna		63	SW	8.15 A	5082 A	415 AB	medium shelf life, cracks
RML 8793VP		63	SW	8.8 A	4978 A	439 AB	large, attractive, similar to Minerva, local sales
Athena		63	SW	6.5 B	5393 A	351 B	firm flesh, good shipper
Minerva		65	SW	8.6 A	4978 A	426 AB	large, very attractive fruit, local sales
LSD2				1.2	2245	146
*	Day from transplanting to first fruit harvested.
1	Means, within a column, followed by the same letter, are not significantly different as determined by LSD (P≤ 0.05).
2	Least Significant Difference, P = 0.05.

Specialty Melon Variety Observation Trial

John Strang, April Satanek, Chris Smigell, Dave Lowry, and Phillip Bush, Department of Horticulture

Introduction

This trial was designed to screen 19 different specialty melon varieties under Kentucky growing conditions. Honeydew, galia, casaba, muskmelon, charentais, and specialty hybrid melons were evaluated in this trial.

Materials and Methods

All varieties were seeded on April 25 into cell packs (72 cells per tray) at the Horticulture Research Farm in Lexington. Cell packs were set on a mist bench with bottom heat until seeds germinated, then moved to a drier, cooler bench in the greenhouse, where the seedlings were thinned to one per cell. Plants were set into black plastic-mulched, raised beds using a waterwheel setter on May 29 and May 30. A single plot of each variety was planted. Each was 36 ft long, with 12 plants set 3 ft apart within the row and 6 ft between rows. Drip irrigation provided water and fertilizer as needed.

Fifty pounds N/A as ammonium nitrate were applied and incorporated into the field prior to bed shaping and planting. The plot was fertigated with a total of 60 lb N/A as ammonium nitrate divided into eight applications. The systemic insecticide Admire 2F was applied as a drench to the base of each plant after planting, using the maximum rate of 24 fl oz/A. Foliar insecticide applications during the season included Sevin and Pounce. Fungicide applications included a pre-plant application of Ridomil Gold and foliar applications of Bravo and Quadris. Curbit preemergent herbicide was applied and incorporated between the rows, just as the vines began to grow off the plastic mulch. Two average-sized fruit of each variety were measured and evaluated for flavor, soluble solids, interior color, and rind color as each variety reached harvest maturity.

Results and Discussion

Admire 2F helped to reduce the number of early cucumber beetles. The growing season was marked with rainy, cool periods, followed by hot, dry periods. The dry weather helped to reduce plant and fruit disease severity, although diseases became more destructive mid- to late season. Very little virus was observed in the plot. Vine cover was thick, with little plant death. Fruit were generally harvested twice a week, more often at the beginning of the harvest period due to the rapid ripening of the galia melons. The weather proved beneficial to most melon varieties. Although the charentais melons did not split as rapidly or as severely as in last year's trial, a considerable amount of fruit was culled due to small cracks.

Honeydews

Honey Dew Green Flesh, Honey Pearl, and San Juan all looked good in this evaluation. All had excellent eating quality and low cull numbers. Honey Pearl had a cream-colored flesh, while the other two varieties had light green flesh. Honey Dew Green Flesh melons were large, averaging 5.6 lb per fruit, while Honey Pearl and San Juan were smaller melons weighing 3.9 lb and 3.7 lb per fruit, respectively. Honey Pearl produced a second crop of quality melons (Tables 1 and 2).

Table 1. Specialty melon variety trial yield and fruit characteristics, Lexington, Kentucky, 2002.
Variety		Melon Type1	Seed Source	Days to Harvest	Yield (cwt/A)2		Avg. No. Melons/A	Avg. Wt./Fruit (lb)	No. Melons/A Culls	Outside Measurements		Flesh Thick. (in.)	Seed Cavity
										Length (in.)	Width (in.)		Length (in.)	Width (in.)
Sundew		HD	SS	85	747.1	a	10900	6.9	173	8.5	7.8	1.8	5.6	4.0
Honey Brew		HD	AC/RU	90	714.4	ab	10100	7.1	432	9.4	7.4	1.9	6.2	3.7
Sweet Delight		HD	RU	90	704.4	ab	9000	7.8	86	8.9	7.8	1.7	5.8	4.6
Sweet Barcelona		CR	BU	84	739.7	ab	6800	10.8	346	14.1	8.3	2.0	10.0	4.0
St. Nick		CR	HR	84	668.3	abc	6600	10.2	346	10.5	7.8	2.4	7.1	3.4
Golden Beauty		CA	JS	80	654.8	abc	9700	6.8	0	10.3	7.4	1.8	7.1	3.8
Dorado		CA	HR	85	654.3	abc	10600	6.2	432	9.5	7.0	1.9	6.4	3.4
HSR 4002B		AN	HL	95-100	580.4	abcd	10400	5.6	432	7.9	6.9	1.7	4.9	3.3
HSR 2528		AN	HL	95	547.9	bcd	10200	5.4	432	8.2	6.6	1.7	5.5	3.5
Dove		AN	HL	75	508.1	cd	10400	4.9	1210	6.8	6.4	1.7	4.0	3.0
Branco Perfecto		SC	SW	92	637.0	abc	7900	8.1	432	9.4	7.3	1.7	5.8	3.7
Sapomiel		PD	UG	94	586.2	abcd	8100	7.2	346	10.8	7.7	1.8	7.6	4.0
Sweet Dreams		GA	SW	79	493.7	cd	7300	6.8	1815	7.7	7.4	2.2	4.3	3.0
Gourmet		SH	HL	73	547.6	bcd	9900	5.6	1988	8.0	7.1	1.9	5.1	3.4
HSR 4011		SH	HL	75-80	417.8	d	7300	5.8	2506	7.0	7.0	1.9	3.5	3.1
1	Melon type: HD = honeydew, CR = Christmas, CA = Canary, SC = Sicilian, PD = Piel de Sapo, AN = ananas, GA = galia, SH = specialty hybrid.
2	Numbers followed by the same letter are not significantly different (Waller-Duncan LSD P = 0.05). Cwt = hundreds of pounds per acre.

Table 2. Specialty melon trial fruit characteristics, Lexington, Kentucky, 2002.
Variety		Flavor (1-5)1	Sugar (%)	Interior Color2	Rind Color3	Fruit Shape	Cracking (1-4)4	Net Type5	Comments
Sundew		4.5	12.8	cr-lg	lg	oval	1	na	Doesn’t slip, attractive exterior and interior.
Honey Brew		4.4	12.5	cr-lg	lg	oval	1.25	na	Doesn’t slip, some surface checking.
Sweet Delight		4.4	12.9	cr-lg	lg	oval	1	na	Doesn’t slip, some oddly shaped, attractive interior.
Sweet Barcelona		2.6	10.4	cr-lg	dg w/yl streaks	oblong	1	na	Doesn’t slip, coarse surface checking, distinctive exterior.
St. Nick		4.3	13.2	cr-wh	dg w/lg streaks	oblong	1	na	Slips at full/over maturity, harvest before slip for storage, light surface checks, crisp flesh, distinctive exterior.
Golden Beauty		4.3	13.4	cr-lg	dy	oblong	1	na	Doesn’t slip, very attractive, wrinkled exterior, harvest when dark yellow.
Dorado		4.6	14.5	cr	dy	oblong	1	na	Doesn’t slip, attractive interior and exterior, harvest when dark yellow.
HSR 4002B		3.0	9.9	lo	tn	oblong	1	md	Stem slips when ripe, attractive.
HSR 2528		2.9	8.9	cr	tn	oval	1	lt	Stem slips when ripe, attractive interior and exterior.
Dove		3.4	10.7	cr	tn	oval	1.3	lt	Stem slips when ripe, becomes overripe very quickly, must be harvested at first sign of exterior yellowing.
Branco Perfecto		4.0	11.6	cr	lg	oblong	1	na	Doesn’t slip, wrinkly exterior, slightly pink cavity walls.
Sapomiel		4.5	13.8	cr	dg w/yl streaks	oblong	1	na	Doesn’t slip, surface checks, large fruit, attractive exterior.
Sweet Dreams		4.6	12.8	lo-cr	gr/yl	oval	1.5	lt	Stem slips when ripe, becomes overripe very quickly, coarse netting, distinctive exterior, attractive interior, must be harvested at the first sign of exterior yellow.
Gourmet		3.8	10.6	cr	tn	oval	1.5	md	Stem slips when ripe, becomes overripe very quickly, attractive exterior, must be harvested at the first sign of exterior yellow.
HSR 4011		3.9	11.0	cr-wh	lg/yl	round	1.5	lt	Stem slips when ripe, coarse netting, distinctive exterior, small seed cavity.
1	Flavor: 1 = poor, 5 = excellent, sweet taste, pleasant texture.
2	Interior color: lo = light orange, cr = cream, lg = light green, wh = white.
3	Rind color: lg = light green, gr = green, dg = dark green, yl = yellow, dy = dark yellow, tn = tan.
4	Cracking: 1 = little or no cracking, 4 = severe cracking and fruit splitting.
5	Net type: lt = light netting, md = medium netting, hv = heavy raised netting, na = none.

Galia Melons

Arava and Sweet Dreams were the best galia melons. Both had excellent eating quality. Arava was judged to have a more attractive exterior and was slightly smaller than Sweet Dreams. It also had very low cull numbers (Table 1). Galia melons must be harvested as soon as the rind starts to turn yellow. Otherwise, the melons rapidly become overripe and are unmarketable. After the initial melon set was harvested, most varieties continued producing fruit, although the number harvested decreased.

Charentais

Four charentais melon varieties were evaluated. None of these performed well in this trial (Tables 1 and 2). It is difficult to visually determine the correct harvest time for charentais melons. Suggested harvest maturity criteria include the yellowing and wilting of the leaf nearest the fruit stem, a change in the rind color from green to grey, and softening of the blossom scar. None of these maturity cues aided in proper harvest timing for this trial. The fruit were mostly either immature or split and decayed when following these criteria.

Miscellaneous melon types

Marygold, a casaba melon, performed very well. It had excellent eating quality and very low numbers of culls. Vanilla Ice, a specialty hybrid melon, was found to have excellent flavor when it was evaluated at the first harvest, but the flavor varied in subsequent harvests. Vanilla Ice melons were not very attractive and had a very short shelf life. HSR 4122, a netted western type cantaloupe, produced well but was not of outstanding quality (Tables 1 and 2).

Acknowledgments

The authors would like to thank Larry Blanford, Barry Duncil, Justin Clark, Stephanie Goode, Courtney Bobrowski, Witoon (Toon) Jaiphon, Sopon (Toni) Issaravut, Takanobu (Bell) Suzuki, Darren Taylor, Eric Bowman, and Spencer Helsabeck for their help with this trial.

Specialty Melon Variety Evaluation

John Strang, April Satanek, John Snyder, Phillip Bush, Chris Smigell, and Dave Lowry, Department of Horticulture

Introduction

Fifteen specialty melon varieties were evaluated in this trial. These included ananas, Christmas, honeydew, galia, canary, Sicilian, Piel de Sapo, and specialty hybrid types of melons. This trial was designed to evaluate a number of different specialty melons under Kentucky conditions.

Materials and Methods

All varieties were seeded on April 25 into cell packs (72 cells per tray) at the Horticulture Research Farm in Lexington. Cell packs were set on a mist bench with bottom heat until seeds germinated, then moved to a drier, cooler bench in the greenhouse, where the seedlings were thinned to one per cell. Plants were set into black plastic-mulched, raised beds using a waterwheel setter on May 29. Each plot was 21 ft long, with seven plants set 3 ft apart within the row and 6 ft between rows. Each plot was replicated four times in a randomized complete block design with 6 ft between replications. Drip irrigation was used to provide water and fertilizer as needed.

Fifty pounds N/A as ammonium nitrate were applied and incorporated into the field prior to bed shaping and planting. The plot was fertigated with a total of 60 lb N/A as ammonium nitrate divided into eight applications over the season. The systemic insecticide Admire 2F was applied to the base of each plant as a drench treatment the day after planting, using the maximum rate of 24 fl oz/A. Foliar insecticide applications during the season included Sevin and Pounce. Fungicide applications included a pre-plant application of Ridomil Gold, and foliar applications of Bravo and Quadris. A pre-emergent herbicide, Curbit was applied and incorporated between the rows as the vines began to grow off the plastic mulch. One fruit from each replication was measured and evaluated for flavor, soluble solids, interior color, rind color, and net type.

Results

The use of Admire 2F helped to reduce the number of early cucumber beetles. Early in the season, cool, rainy weather prevailed, and this was followed by hot, dry periods. The dry weather helped to reduce the severity of some diseases, although disease became more destructive mid- to late season. Very little virus was observed in the plot. Early vine cover was thick, with little plant death. Plants were generally harvested twice a week, more often at the beginning due to the quick ripening of the galia and ananas type melons.

Honeydew type

Sundew and Honey Brew performed very well. These melons were also two of last year's best performers, with high yield (Table 1) and high sugar (Table 2). Sweet Delight also performed well, but it produced some oddly shaped fruit, making it less marketable. This season the honeydews exhibited less surface checking and developed a slight yellow blush when fully ripe.

Table 1. Specialty melon fruit characteristics from single plots, Lexington, Kentucky, 2002.
Variety		Melon Type1	Seed Source	Days to Harvest	Yield2 (cwt/A)	Avg. No. Melons/A	Avg. Wt./Fruit (lb)	Culls (%)	Exterior Fruit		Flesh Thick. (in.)	Seed Cavity
									Length (in.)	Width (in.)		Length (in.)	Width (in.)
Honey Dew Green Flesh		HD	RU	90	797.1	14300	5.6	0	8.9	7.3	1.6	5.8	3.9
HSR 4156		HD	HL	90-95	765.8	13700	5.6	0	7.5	7.1	1.9	4.4	3.0
Fantasma		HD	HM	85	663.0	9300	7.1	13.2	8.7	7.7	2.1	5.5	3.5
Honey Pearl		HD	JS	80	631.2	16300	3.9	2.4	7.4	6.7	1.9	4.2	3.0
Morning Ice		HD	HM	85	479.0	6900	7.0	27.6	9.1	7.3	2.0	6.0	3.3
San Juan		HD	RU	75	476.0	12900	3.7	4.4	6.5	6.3	1.8	4.0	2.8
HSR 4054		GA	HL	85	635.3	11900	5.3	3.2	7.2	6.8	2.0	4.6	2.7
HSR 4036		GA	HL	70	559.1	11700	4.8	3.3	7.0	6.4	1.9	4.2	2.6
Arava		GA	JS	77	545.0	12300	4.4	3.1	6.7	6.8	1.8	4.0	3.0
Sweet Dreams		GA	SW	79	412.4	6300	6.6	13.8	7.9	7.2	2.0	4.4	3.1
Passport		GA	HL	75	375.7	7100	5.3	10.2	6.8	6.5	2.0	3.9	2.5
Crete		GA	ST	88	300.0	6500	4.6	5.8	7.4	6.6	1.9	4.7	2.8
Honey Girl Hybrid		CH	BU	75	388.2	9900	3.9	24.6	6.4	6.4	1.5	3.7	3.1
French Orange		CH	HR	75	359.5	12300	2.9	24.6	5.6	5.2	1.5	3.4	2.2
Savor		CH	JS	78	152.3	7100	2.2	45.3	5.4	5.6	1.5	3.2	2.5
Edonis		CH	JS	70	94.3	3200	2.9	71.4	6.6	5.9	1.7	4.1	2.3
Marygold		CS	RU	92	615.6	16500	3.7	1.2	7.3	6.0	1.6	4.5	3.0
Vanilla Ice		SH	BU	80	660.5	13500	4.9	5.6	6.9	6.7	1.9	4.3	3.0
HSR 4122		MM	HL	80-95	441.7	11100	4.0	1.1	6.5	6.2	1.8	4.0	2.8
1	Melon type: HD = honeydew, GA = galia, CS = casaba, CH = charentais, SH = specialty hybrid, MM = muskmelon.
2	Cwt = hundreds of pounds per acre.

Table 2. Specialty melon fruit and vine characteristics from single plots, Lexington, Kentucky, 2002.
Variety		Flavor (1-5)1	Sugar (%)	Flesh Color2	Rind Color3	Fruit Shape	Cracking (1-4)4	Net Type5	Comments
Honey Dew Green Flesh		4.3	12.6	lg	lg/cr	oval	1	na	Doesn’t slip, firm flesh.
HSR 4156		3.3	10.0	cr-lg	lg/cr	oval	1.5	na	Doesn’t slip, uniform, attractive exterior, minimal checking.
Fantasma		4.0	12.6	lg	wh/gr	oval	1	na	Doesn’t slip, attractive, oddly shaped.
Honey Pearl		4.0	13.2	cr	cr/wh	oval	1	na	Doesn’t slip, attractive, has a few small, light yellow spots when ripe, very good taste, large second set of high quality melons.
Morning Ice		4.3	13.4	cr-lg	lg	oval	1	na	Doesn’t slip, surface checking near stem, not uniform in shape.
San Juan		4.0	15.5	lg-gr	lg/cr	round	1	na	Doesn’t slip, small melon, nice, sweet flavor.
HSR 4054		3.3	10.5	lg-gr	gr/yl	oval	1.5	md	Stem slips when ripe, some variability in fruit size and shape.
HSR 4036		3.4	9.0	lg-gr	gr/yl	oval	1	lt	Stem slips when ripe, yellow rind indicates ripeness, attractive exterior and interior.
Arava		4.5	10.4	lg-gr	yl/gr	round	1.5	md	Stem slips when ripe, very attractive.
Sweet Dreams		4.3	12.3	lg	gr/yl	oval	1.5	lt	Stem slips when ripe, consistent quality.
Passport		3.2	7.3	cr-gr	gr/yl	oval	2	md	Stem slips when ripe, attractive exterior and interior.
Crete		3.5	12.8	ly-gr	gr/yl	oval	1	md	Stem slips hard and fruit still green when ripe, quality not consistent.
Honey Girl Hybrid		4.0	10.8	do	tn w/sutures	round	1	na	Pick at half slip, taste is distinctive.
French Orange		4.5	11.5	do	tn	round	1	md	Pick at half slip, consistent taste.
Savor		3.4	11.0	do	tn w/sutures	round	3.5	na	Pick at half slip, cracked severely and split open.
Edonis		3.8	11.4	do	tn/gr w/sutures	round	3	lt	Pick at half slip, cracked severely at blossom end.
Marygold		4.0	12.9	cr	dy	oval	1	na	Doesn’t slip, slight checking.
Vanilla Ice		5.0	12.1	ly	gr/yl	round	1	lt	Stem slips when ripe, mature when green and yellow speckled, slight surface checking, good flavor, variable quality among harvests.
HSR 4122		3.8	10.6	or	tn	round	1	md	Stem slips when ripe.
1	Flavor: 1 = poor, 5 = excellent sweet taste, pleasant texture.
2	Flesh color: lg = light green, cr = cream, or = orange, do = dark orange, gr = green, ly = light yellow.
3	Rind color: lg = light green, gr = medium green, cr = cream, or = orange, yl = yellow, dy = dark yellow, tn = tan, wh = white.
4	Cracking: 1 = little or no cracking, 4 = severe cracking and fruit splitting.
5	Net type: lt = light netting, md = medium netting, hv = heavy, raised netting, na = none.

Christmas type

The Christmas type melons in this trial were St. Nick and Sweet Barcelona. Although Sweet Barcelona had the higher yield, St. Nick had a more desirable flavor as well as a higher sugar content (Table 2). These are large melons averaging more than 10 pounds, and they have a distinctive taste as well as a very crisp, white flesh. For storage, Christmas melons should be harvested before slip. Slight checking of the surface was observed at maturity.

Canary type

Golden Beauty and Dorado were both excellent melons, and marketable yields were identical (Table 1). Dorado was slightly smaller than Golden Beauty and was judged to taste slightly better than Golden Beauty (Table 2); however, Golden Beauty did not produce any cull melons. Both varieties had excellent quality, were very attractive, and were observed to store for an extended period under refrigeration and to maintain eating quality.

Ananas type

Three ananas type melons were evaluated, HSR 4002B, HSR 2528, and Dove. Yield was about the same for all three varieties (Table 1). None of the ananas melons were judged to perform well in these trials. These varieties also ripen rapidly and were prone to decay if not picked promptly.

Miscellaneous melon types

Sapomiel, a Piel de Sapo melon, performed very well. It was attractive, similar to a Christmas melon, and had an excellent flavor. Sweet Dreams, a galia type melon, had an excellent taste and high sugar content. This is an excellent quality melon for local sales; however, the exterior is not as attractive as we would like. Branco Perfecto, a Sicilian melon, looked very much like a honeydew, except it had the wrinkly skin characteristic of a canary melon. Branco Perfecto did not have the exceptional sugar content and eating quality that we would like. The two specialty hybrid melons, Gourmet and HSR 4011, both ripened rapidly and had an off-flavor, particularly if they were a little overripe.

Acknowledgments

The authors would like to thank Darrell Slone, Larry Blanford, Barry Duncil, Justin Clark, Stephanie Goode, Courtney Bobrowski, Witoon (Toon) Jaiphong, Sopon (Toni) Issaravut, Takanobu (Bell) Suzuki, Darren Taylor, Eric Bowman, and Spencer Helsabeck for their help with this trial.

Seeded and Seedless Watermelon Variety Trial

John Strang, April Satanek, John Snyder, Darrell Slone, Dave Lowry, and Phillip Bush, Department of Horticulture

Introduction

Seventeen triploid (seedless) and 10 seeded watermelon varieties were evaluated in this trial. One orange and several golden and yellow fleshed varieties were also included.

Materials and Methods

All varieties were sown in cell packs (72 cells/tray) on April 25. Trays were placed on a bench with bottom heat in a warm greenhouse. Once seeds had germinated, the seedlings were counted to obtain a germination percentage. The seedlings were then thinned to one per cell, and the trays moved to a slightly cooler house. On June 10, the watermelon plants were set into raised, plastic mulched beds using a water wheel setter. Each plot was 24 ft long, containing six plants, with 4 ft between plants within the row. Between row spacing was 10 ft. Each plot was replicated four times in a randomized complete block. Drip irrigation was used to irrigate and fertigate as needed.

Fifty pounds N/A as ammonium nitrate was applied preplant. A total of 47 lb N/A as ammonium nitrate was fertigated over seven applications throughout the season. Irrigation was halted about four weeks before harvest to increase melon sugar levels.

A systemic insecticide, Admire 2F, was applied as a drench to the base of each plant soon after planting, at the rate of 24 fl oz per acre. The foliar insecticide Sevin was also used for insect control. Fungicide sprays included a soil-applied, pre-bedding treatment of Ridomil Gold and a foliar application of Bravo and Quadris fungicides. The pre-emergent herbicide Curbit was applied between rows before vine coverage. One fruit from each replication was measured and evaluated for soluble solids, flavor, hollowheart, average seed number per fruit, and interior color.

Results and Discussion

Overall, watermelon quality was excellent, but yields were considerably lower compared to previous years. Extreme heat at the time of second set may have reduced fruit set and yields. There were very little fungal, viral, or insect problems, but morningglory became a problem later in the season. The low seed germination rates were probably accentuated by excess moisture following seeding.

Seedless Watermelons

Triple Prize was one of the best performing seedless varieties in this trial. Revolution, Freedom, HSR 2908, Cooperstown, and Tri-X Shadow also had excellent quality (Tables 1 and 2). HSR 2908 has a very attractive, dark, Jubilee-type rind. Trillion had a very high yield, but its flavor was not as good as we would like. Millionaire and Super Seedless 7167 had unacceptable seed numbers. Treasure Chest was the best seedless yellow watermelon. US 3281, the only orange-fleshed seedless watermelon, was very good. However, it had a fair amount of hollowheart. This could have been accentuated by the high level of nitrogen fertilizer used in this study.

Table 1. Seeded and seedless watermelon variety trial yield and fruit characteristics, Lexington, Kentucky, 2002.
Cultivar		Seed Source	Germ. Rate (%)	Melon Type1	Melon Shape	Days to Harvest	Yield (cwt/A)2		Avg. No. Mkt. Fruit/ A	Avg. Wt/Fruit (lb)	No. Fruit/A <10 lb	Outside Measurements
												Length (in.)	Width (in.)
Sangria		RG	88	S	elongate	85	833.1	a	4300	19.5	0	17.6	8.3
Trillion		RU	94	T	round	90	828.3	ab	6100	13.5	0	10.4	8.4
Royalty		RU	90	S	elongate	85	807.6	abc	4000	20.0	91	15.0	9.4
Millionaire		HM	65	T	round	92	805.6	abc	5800	14.0	91	11.3	9.2
Stars N’ Stripes		SI	100	S	elongate	85	788.6	abc	4500	17.6	0	18.3	8.8
Summer Flavor 800		AC	47	S	elongate	85	763.0	abc	3800	20.3	0	16.5	9.5
Triple Prize		RU	85	T	round	82	756.3	abc	5400	13.9	0	10.5	9.6
Emperor		RU	96	S	elongate	82	725.3	abcd	3500	21.0	45	15.3	10.2
Super Seedless 7167		AC	44	T	oval	85	723.7	abcd	5400	13.4	0	11.5	9.2
Treasure Chest		RU	38	T, Y	round	80	711.7	abcd	6200	11.4	0	8.5	9.1
Delta		RU	91	S	elongate	82	696.7	abcd	3200	22.0	0	14.2	9.8
US 3281		US	60	T, O	round	85	694.2	abcd	4900	14.0	45	10.6	10.4
Summer Gold		SW	100	S, G	elongate	83	690.4	abcd	2700	25.8	0	15.3	10.1
Revolution		ST	69	T	elongate	85	683.8	abcd	4400	15.5	45	13.7	9.2
AU Golden Producer		RU	80	S, G	round	90	674.5	abcd	2800	24.0	0	12.3	11.2
Freedom		ST	40	T	elongate	85-90	659.7	abcd	4200	15.6	0	13.2	9.1
HSR 2908		HL	39	T	round	87	657.9	abcd	4700	14.0	91	9.7	9.4
Cooperstown		RU	16	T	round	85	657.0	abcd	4600	14.3	0	10.8	9.6
Imperial		RU	88	S	oval	85	650.5	abcd	4200	15.4	0	12.3	6.6
Tri-X-Shadow		SW	51	T	round	89	644.3	abcd	5200	12.3	0	10.8	8.7
HMX 8914		HM	33	T	round	85	634.9	abcd	4100	15.4	0	10.7	10.2
Ultra Cool		SI	12	T	round	75	630.4	abcd	4700	13.4	45	10.0	9.6
Amarillo		ST/RU	38	T, Y	round	80	590.1	abcd	5400	10.9	182	10.0	9.6
Talladega		SI	14	T	round	83	586.3	bcd	4300	13.6	45	10.8	9.2
HSR 2914		HL	25	T	round	85	582.3	cd	4700	12.5	0	10.9	9.3
Sugarheart		SI	47	T	round	85	508.2	de	3800	13.5	0	11.1	9.4
Golden Crown Hyb.		JU	88	S	oval	78	307.2	e	4700	6.5	227	9.5	7.1
1	Melon type: S = Seeded, T = Triploid (seedless); all varieties had red flesh color unless otherwise noted as: G = gold, O = Orange, Y = yellow.
2	Numbers followed by the same letter are not significantly different (Waller-Duncan LSD P = 0.05). Yield is based on all melons >10 lb in hundred lb (cwt) per acre.

Seeded Watermelons

Sangria, Royalty, and Stars N' Stripes were all excellent seeded, red-fleshed watermelons (Tables 1 and 2). Summer Gold and AU Golden Producer were both large, excellent quality, golden-fleshed seeded watermelons; however, Summer Gold had more hollowheart than we would like to see.

Table 2. Seeded and seedless watermelon variety trial fruit characteristics, Lexington, Kentucky, 2002
Variety		Soluble Solids (%)	Flavor (1-5)1	Hollow Heart (1-2) 2	Rind Thick. (in.)	Avg. Seed No./Fruit3	Interior Color4	Rind Type5	Comments
Sangria		11.5	4.5	1.8	0.7	na	red	AS	Consistent high quality, some tapered at one end.
Trillion		10.4	3.4	2.0	0.6	5.3	pk	CS	Seeds are very tiny.
Royalty		11.3	4.4	2.0	0.7	na	pk red	RS	Thin rind, some fibers in the flesh.
Millionaire		10.4	3.3	2.0	0.7	24.3	pk red	CS	Seeds are very tiny.
Stars N’ Stripes		10.6	4.7	1.8	0.7	na	pk red	CS	Attractive exterior and interior, flesh is medium firm with good flavor.
Summer Flavor 800		12.0	4.2	1.5	0.7	na	red	RS	Attractive exterior and interior, nice flavor.
Triple Prize		10.6	4.0	1.8	0.9	4.3	red	dk CS	Nice flavor.
Emperor		11.0	4.1	1.8	0.7	na	pk red	CS	Large melon.
Super Seedless 7167		10.6	3.7	2.0	0.7	17.8	pk red	RS	Ground spot dark yellow when ripe, attractive red interior.
Treasure Chest		9.6	3.6	1.8	0.7	1.3	br yl	CS	Tough rind, very attractive, some dark seed traces.
Delta		11.7	4.2	2.0	0.6	na	red	CS	Attractive exterior and interior, thin rind, nice red interior.
US 3281		10.7	3.9	1.3	0.9	4.3	orange	CS	Very attractive, light seed traces, good color, hollowheart, fibers in fruit.
Summer Gold		11.1	4.4	1.3	0.7	na	gld	RS	Attractive interior and exterior, very large melon, pleasant, sweet flavor.
Revolution		10.9	4.3	2.0	0.7	2.8	br red	RS	Attractive dark green rind, firm flesh.
AU Golden Producer		11.3	4.4	1.8	0.7	na	gld	RS	Attractive interior and exterior, very large melon, thin rind at blossom end.
Freedom		11.3	4.6	1.8	0.7	3.8	red	dk JU	Attractive melon, attractive interior.
HSR 2908		11.6	4.5	2.0	0.7	2.3	pk	dk JU	Attractive dark green, tough rind, firm flesh, excellent flavor.
Cooperstown		10.9	4.5	2.0	0.6	5.3	red	CS	Rind stripes are speckled and fragmented, excellent bright red interior.
Imperial		10.3	4.1	2.0	0.5	na	br red	RS	Attractive exterior and interior color.
Tri-X-Shadow		10.4	4.6	1.5	0.6	0	pk red	BK	Attractive exterior and interior, excellent flavor.
HMX 8914		10.9	4.4	2.0	0.7	5.7	pk red	CS	Attractive exterior and interior, pleasant flavor.
Ultra Cool		10.6	3.7	1.7	0.7	0.7	pk red	RS
Amarillo		10.0	3.5	1.5	0.7	3.3	br yl	JU	Attractive exterior and interior, seeds are gray.
Talladega		10.3	4.0	1.8	0.7	1.8	pk red	CS	Nice red interior.
HSR 2914		11.6	4.2	2.0	0.6	1.8	pk red	dk JU	Very attractive exterior and interior, firm flesh, excellent flavor.
Sugarheart		10.4	3.9	2.0	0.7	0.5	dk pk	CS
Golden Crown Hyb.		9.3	3.2	1.8	0.3	na	dk red	yellow	Very thin, fragile rind splits easily, ripens before tendril dies.
1	Taste rating: 1 = poor, 5 = excellent.
2	Hollowheart rating: 1 = hollowheart, 2 = no hollowheart.
3	na: not applicable, seeds were not counted in the seeded varieties.
4	Flesh color: lt = light, dk = dark, pk = pink, br = bright, yl = yellow, gld = gold.
5	Rind type: AS = Allsweet, medium green rind w/dark green, broad mottles stripes; JU = Jubilee, light green rind w/distant, narrow, dark green stripes; BK = Black, solid dark green rind; CS = Crimson Sweet, light green rind w/mottled, dark green stripes; RS = Royal Sweet, light green rind w/wide, mottled, dark green stripes, dk = dark.

Acknowledgments

The authors would like to thank Larry Blanford, Barry Duncil, Justin Clark, Stephanie Goode, Courtney Bobrowski, Witoon (Toon) Jaiphong, Sopon (Toni) Issaravut, Takanobu (Bell) Suzuki, Darren Taylor, Eric Bowman, and Spencer Helsabeck for their help with this trial.

Squash Bug Control and Impact on Cucurbit Yellow Vine Decline in Acorn Squash

Ric Bessin, William Nesmith, and Brent Rowell, Departments of Entomology, Plant Pathology, and Horticulture

Introduction

Squash bug can cause serious losses in summer squash, winter squash, and pumpkins in Kentucky. While all of the melon and squash crops can be attacked, the insect shows a preference for squashes and pumpkins. Squash bugs can be very difficult to control when populations are allowed to build during the summer. The insects damage plants by removing sap and causing leaves to wilt and collapse. Young plants and infested leaves on older plants may be killed directly by this pest. Typically, squash bugs begin to colonize fields about the time the vines begin to run. They remove plant sap with their piercing-sucking mouthparts. Soon after beginning to feed, they start laying eggs, primarily on the undersides of leaves in the angles between veins. The bronze eggs are football-shaped and lie on their sides in groups of 12 or more. Eggs hatch in one to two weeks. Young nymphs are green with black legs, while older nymphs are light gray.

During the past decade, a disease causing yellowing and sudden decline of cucurbit vines has been recognized mainly in the south-central states. The disease is called Cucurbit Yellow Vine Decline (CYVD). CYVD was first reported from Texas and Oklahoma, but other states in the South and Midwest also reported it after diagnostic protocols were established. Recently, CYVD was confirmed from several locations in Kentucky on squash, pumpkin, watermelon, and muskmelon. It is important to appreciate that this is a newly diagnosed disease in Kentucky, rather than a new disease. Thanks to persistent researchers from the USDA-ARS in Oklahoma, Texas A&M, and Oklahoma State University, the techniques became available late last summer to satisfy the rules of proof necessary to make a definitive diagnosis. We used their techniques in making the diagnosis in our laboratories, plus had confirmation from the laboratory of Dr. Benny Bruton, USDA-ARS, Lane, Oklahoma. It is now known that the causal agent is a phloem-limited bacterium, Serratia marcescens. It appears to survive in, and is transmitted to, cucurbits by the squash bug.

Symptoms of CYVD are variable, depending on plant species involved, age of plant at the time of infection, and other factors. Symptoms include the following: some plants show considerable stunting and yellowing (probably those infected early), while young fast-growing plants (that probably become infected later) may suddenly collapse without yellowing. Other plants (apparently infected later) develop striking yellow vines and decline slowly as fruits approach maturity. In watermelon, we noticed that the terminals of runners tend to become more vertical (stand up) with rolled leaves. To diagnose the disease, select plants with the above symptoms, and make cross-sectional cuts into the phloem tissues in the primary root and crown, looking for the development of a distinct golden to honey-brown discoloration of the phloem. The roots and lower stems of such plants are quickly colonized by a number of microbes that help finish the kill, and these secondary invaders will complicate diagnostic efforts. The phloem tissues in a cross-sectional cut in the lower stem appear just inside the outer layer of the stem as a series of arcs, wedges, or continuous zones (depending on age of tissue) that cap the xylem ( the woody tissue with the large pores). Healthy phloem should be translucent to green, rather than yellow to browning.

Materials and Methods

A study was conducted at the UK Horticultural Research Farm in Lexington during the summer of 2002 to evaluate the effectiveness of three control methods for squash bug on acorn squash and the impact of that control on the incidence of cucurbit yellow vine decline. Four-week-old Table Gold acorn squash plants were transplanted on June 11 into raised beds with black plastic and trickle irrigation. The Table Gold cultivar was selected as it had a high level of yellow vine decline in a variety trial in 2001. Plants were spaced 18 inches apart in single rows; beds were 6 ft from center to center. Each experimental plot consisted of four rows of 15 squash plants each. Between each plot, a 30-ft-wide band of Jackpot sweet corn was transplanted into the rows to reduce squash bug and cucumber beetle movement between plots.

The commercially available squash bug treatments examined were Pounce 3.2 EC applied as a foliar spray at a rate of 6 fl oz/application, Admire 2F applied as a post-transplant drench at 20 fl oz/acre, and Platinum 2 SC applied as a post-transplant drench at 6.5 fl oz/acre. The study also included an untreated control plot. The Pounce 3.2 EC sprays were applied on June 11 and 21. The Admire and Platinum treatments were applied directly to the soil at the base of the plants in 1/3 oz of water on June 11, immediately after transplanting. The post-transplant drench was selected to minimize worker exposure to insecticide residues while trying to maximize rapid uptake of the insecticide for squash bug and cucumber beetle control. The Admire and Platinum were intentionally not mixed with the transplant water because this type of application is prohibited. All application methods used in this study are labeled for commercial use.

Prior to harvest, squash bug and cucumber beetle numbers were monitored periodically on five plants in each plot. Plants within the plots were examined on three dates for the occurrence of symptoms of CYVD (yellowing, wilting, and plant loss). Data were subjected to analysis of variance, and means were compared using Fisher's Protected LSD.

There was a sprayer problem with the Pounce treatments that was probably the result of herbicide contamination in the backpack sprayer used to treat the plots. This did cause some leaf burning and distortion that confounded initial yellow vine decline symptom assessment on the July 10 sampling date.

Results and Discussion

In this study, the squash bug moved into the plots quickly and was observed in the untreated plots on the first sampling date, June 21 (Table 1). Squash bugs were common in all plots by the third sampling date. Both systemic treatments and the foliar treatment significantly suppressed squash bug adults through the June sampling dates, but only Platinum continued to significantly reduce levels on July 6. Egg masses deposited by squash bugs were first detected on June 27, and all treatments reduced egg mass numbers through July 7. More striped cucumber beetles were captured in untreated plots than in any of the treated plots for all sampling periods.

Table 1. Numbers of insects per five acorn squash plants.
Treatment		Cucumber Beetles				Squash Bug Adults				SB Egg Masses
		Jun. 211	Jun. 27	Jul. 6		Jun. 21	Jun. 27	July 6		Jun. 27	Jul. 6
Pounce 3.2EC		0.8 b	0.0 b	15.3 a		0.0 b	0.0 b	2.8 ab		0.0 b	0.8 b
Admire 2F		0.0 b	1.5 b	4.8 ab		0.3 b	1.5 b	4.5 ab		0.0 b	0.5 b
Platinum 2SC		0.3 b	0.8 b	4.0 b		0.0 b	0.0 b	1.8 b		0.0 b	0.8 b
Untreated		6.3 a	7.8 a	13.3 ab		6.0 a	4.5 a	7.0 a		6.0 a	13.0 a
1	Means in the same column followed by the same letter are not significantly different (LSD P < 0.05).

On the first sampling date for symptoms of CYVD, only the Admire treatment reduced the number of plants with symptoms as compared to the untreated control (Table 2). By the second sampling date six days later, all of the treatments displayed a few plants with symptoms of the disease. However, by the final sampling period, all of the plots had similar percentages of plants with symptoms of the disease. During the July 25-30 sampling period, random plants displaying symptoms of CYVD were examined and confirmed to have Serratia marcescens, the causal agent of the disease. Each of the insecticide treatments significantly reduced the numbers of dead plants compared to the untreated control on each of the examination dates. By July 24, nearly 40% of the squash plants in the untreated plots were dead.

Table 2. Percentage of plants with yellow vine decline symptoms and numbers of dead plants.
Treatment		% Yellow Vine Decline				Number of Dead Plants
		July 101	July 16	July 25/302		July 11	July 16	July 24
Pounce 3.2 EC		42.5 ab	49.6 b	70.0 a		3.0 b	4.3 b	10.0 b
Admire 2 F		34.6 b	45.8 b	69.2 a		1.3 b	1.3 b	3.0 b
Platinum 2 SC		38.3 ab	47.9 b	82.5 a		1.0 b	1.3 b	3.3 b
Untreated		68.8 a	76.7 a	88.8 a		11.3 a	12.8 a	23.8 a
1	Means in the same column followed by the same letter are not significantly different (LSD P < 0.05).
2	Yellow vine decline was rated over a 5-day period, one block each day.

Yields, fruit per plot, and average fruit weight were significantly higher in each of the insecticide-treated plots compared with the untreated control (Table 3). However, the systemic treatments outyielded, in terms of total fruit weight and number, the two foliar applications of Pounce.

Table 3. Acorn squash yields per plot, fruit number, and weight per fruit.
Treatment		Weight of Fruit (lb)1	No. of Fruit	Weight per Fruit (lb)
Pounce 3.2 EC		47.4 b	47.8 b	0.99 a
Admire 2 F		104.4 a	100.0 a	1.04 a
Platinum 2 SC		122.9 a	117.3 a	1.05 a
Untreated		21.3 c	26.0 c	0.79 b
1	Means in the same column followed by the same letter are not significantly different (LSD P < 0.05).

This study indicates that CYVD is a significant disease that can seriously limit squash production when not effectively controlled. As this disease is known to be vectored by the squash bug, management of the disease is dependent on squash bug management. Although neither Admire or Platinum lists squash bug on the label, both products provided significant squash bug reductions that resulted in delay of the onset of the disease and higher yields in this study. By the end of the study, all of the treatments had equal infection rates, although the delay in development of the disease in the insecticide-treated plots resulted in reduced severity.

Both Admire and Platinum are approved for soil application to squash for other insect pests. In this study, two foliar applications of Pounce also provided significant squash bug reductions, fewer diseased plants, and an increase in yield compared to the untreated control. It is to be expected that higher levels of control would result from additional foliar applications.

Biological Control of European Corn Borers in Bell Peppers

Karen Friley, Brent Rowell, and Ric Bessin, Departments of Entomology and Horticulture

Introduction

By adopting integrated pest management practices, commercial pepper growers in Kentucky have been able to reduce pesticide use and have been able to use them more effectively. Biological control is a difficult and often overlooked component of IPM programs for vegetable crops. Biological control techniques generally attempt to mimic natural controls in that they use a living "natural enemy" of the target pest in question to keep that pest in check, thereby eliminating or reducing the need for pesticides.

The European corn borer (ECB), Ostrinia nubilalis, is a serious pest of sweet corn and the primary pest of bell peppers in Kentucky. In Kentucky, damage to pepper crops is most prevalent during the middle to latter part of the growing season and is inflicted by second and third generation ECB larvae. After hatching, these larvae tunnel under the caps of pepper fruits, thereby rendering the larvae safe from pesticides. This makes the timing of any control treatment—whether pesticides or biological control—of great significance.

Recent studies in the northeastern United States have shown that the use of parasitic wasps from the genus Trichogramma has been effective against ECB larvae in sweet corn. After a successful preliminary trial in 2001, the University of Kentucky Entomology and Horticulture Departments began a joint two-year study in 2002 to determine the feasibility of inundative releases of the egg parasite Trichogramma ostriniae (T.o.) to control ECB in bell peppers. Researchers at Pennsylvania State University and Virginia Polytechnic Institute and State University began similar studies with T.o. in peppers in 2002 in collaboration with the University of Kentucky. Researchers at Cornell University, the University of Maine, and the University of Massachusetts also began further studies with T.o. in sweet corn in 2002.

Materials and Methods

Five locations within a 35-mile radius of Lexington, Kentucky, were chosen as release sites for this study. Peppers were grown with conventional production methods at three sites and with organic methods (certified organic) at two locations. Conventional field plots were located at the University of Kentucky Horticulture Research Farm ("South Farm," SF) and at the UK Spindletop Research Farm ("North Farm," NF), both at Lexington in Fayette County. The third conventional site was located within a commercial pepper grower's field in Scott County (SC). The two locations using organically approved production methods were at the students' CSA farm at Berea College (BC) in Madison County and at Kentucky State University's (KSU) Research and Demonstration Farm in Franklin County.

Two bacterial spot-resistant bell pepper cultivars, Aristotle and Early Sunsation, were used for these experiments. Aristotle was used at SF, SC, and BC, while Early Sunsation was used at NF and KSU (Table 1). Plants were started at the greenhouse at the South Farm where they were grown conventionally or organically, depending on final destination. Peppers for the conventional plots were sown 20 March and transplanted to 72-cell trays on 4-5 April. Peppers for the organic plots were sown on 2 April and were transplanted to 72-cell trays on 19 April. The commercial grower produced his own transplants (cv. Aristotle) at SC. Peppers were transplanted to the field on the dates shown in Table 1.

Table 1. Test locations, cultural practices, and cultivars used in control and Trichogramma ostriniae release plots in Central Kentucky, 2002.
Location1		Transplanting Date	Growing System2	Cultivar	Cultural Practices3
SF		24 May	Conv	Aristotle	RB,DR,P
NF		5 June	Conv	Early Sunsation	RB,DR,P
SC		16 May	Conv	Aristotle	RB,DR,P
BC		29 May	Organic	Aristotle	SR,B
KSU		24 May	Organic	Early Sunsation	SR,P
1	SF = South Farm, NF = North Farm, SC = Scott County, BC = Berea College, KSU = Kentucky State University.
2	Conv = grown using conventional practices, Organic = grown under certified organic conditions.
3	RB = raised beds, DR = Double Rows, P = black plastic mulch with drip irrigation, SR = single rows, B = bare ground.

Peppers were transplanted into raised beds with black plastic and drip irrigation at SF, NF, and SC. At SF, NF, and SC, peppers were grown in two rows/bed with plants 12 inches apart in the rows and 15 to 16 inches between the double rows. Peppers were grown in single rows at BC and KSU. Beds or single rows were approximately 6 ft between centers at each location. Black plastic mulch was used at KSU, while peppers were grown on bare ground at BC (Table 1). Drip irrigation was used at all locations. Conventional plots at SF and NF received preplant applications of 50 lb N/A and supplemental "fertigated" applications totaling 40 lb N/A during the growing season. Phosphorus and potassium were applied prior to planting according to soil test results at these two locations. Organic plots at KSU received preplant applications of compost. A cover crop of white clover was plowed under prior to planting at BC. Plots at BC and KSU received supplemental liquid organic nitrogen fertilizer through the drip system (Phitamin 800, Peaceful Valley Farm Supply, Grass Valley, CA). Extensive cultivation and hoeing was required for weed control at BC, while herbicides and two cultivations were required in conventional plots. No insecticides were used in plots at any of the five locations, while fixed copper was used for bacterial spot prevention at the conventional sites.

Treatments at each location consisted of a control (no release) plot and a T.o. release plot. The two plots were 1,000 ft apart except for SC where that separation distance was not possible because of the limited overall size of the grower's field. Plots were only 300 ft apart at SC. Each release plot was located downwind from each control plot to reduce the possibility of T.o. being blown into the control plot. ECB pheromone traps (Texas cone traps) were placed adjacent to each plot to monitor timing and numbers of ECB moth flights. The traps were checked and emptied weekly, and the numbers of ECB moths recorded. Pheromone lures were replaced monthly.

Trichogramma ostriniae were purchased from IPM Laboratories Inc., Locke, New York, and sent by overnight express to arrive within a day or two of the scheduled release dates. These came in the form of parasitized Ephistia kuehniell eggs, which had been glued onto cards that were perforated into 1-inch square sections. The number of squares needed was calculated for each release plot, as plots were not all the same size. A total release of 450,000 T.o./A was made at each location. This total was divided among three releases of 150,000 T.o./A per release.

T.o. release dates were chosen in accordance with a degree-day model predicting egg laying of second-generation ECB at each location. Releases began on or near the model-predicted date for the initiation of second-generation ECB egg laying at that location. The second and third releases at each location corresponded to model-predicted 25% and 75% completion of egg laying (Table 2). Squares containing the T.o. were placed into cardboard "hangers" provided by IPM Laboratories. These were folded, stapled, and hung on pepper plants in the center of each release plot. The hangers protected T.o. from predators while allowing the parasites to exit through small spaces at the edges of the folded cardboard.

Table 2. Release dates for Trichogramma ostriniae at five Central Kentucky locations, 2002.
Location1		System2	1st Release	2nd Release	3rd Release
SF		Conv	10 July	18 July	25 July
NF		Conv	10 July	18 July	25 July
SC		Conv	10 July	18 July	23 July
BC		Organic	26 June	9 July	17 July
KSU		Organic	10 July	17 July	24 July
1	SF = South Farm, NF = North Farm, SC = Scott County, BC = Berea College, KSU = Kentucky State University.
2	Conv = grown using conventional practices, Organic = grown under certified organic conditions.

Twenty sentinel ECB egg masses, provided by the USDA lab at Iowa State University, were pinned to the undersides of pepper leaves in the border rows of both the control and release plots at the time of each release and at weekly intervals thereafter until final harvests. These were used to determine the percentage of parasitization at each location and to help determine whether Trichogramma ostriniae were establishing themselves. These egg masses were retrieved after 48 to 72 hours, placed into gelatin capsules, and stored in a temperature-controlled cabinet at 74°F.

Treatment plot sizes varied among locations; each plot was approximately 1,500 ft² (500 plants/plot in double rows) at the three conventional sites and approximately 3,000 ft² (500 plants/plot in single rows) at the two organic sites. All rows of each plot except the border rows were harvested to determine yields and ECB infestation levels. Correction factors were used to equalize plot sizes among all locations when yields were calculated and compared. Peppers were harvested and separated into insect-damaged and undamaged fruits and then sorted again according to USDA grades before they were counted and weighed. All fruit appearing to be insect-damaged were carefully dissected to look for ECB larvae. The number of ECB-damaged or infested fruits as well as the number of larvae found within each fruit were recorded. The number of times plots were harvested varied by location (Table 3).

Table 3. Bell pepper harvest dates at five locations in Central Kentucky, 2002.
Location1		1st Harvest	2nd Harvest	3rd Harvest
SF		17 July	6 Aug	22 Aug
NF		31 July	14 Aug	--
SC		23 July	29 July	4 Sept
BC		5 Aug	27 Aug	--
KSU		14 Aug	--	--
1	SF = South Farm, NF = North Farm, SC = Scott County, BC = Berea College, KSU = Kentucky State University.

Yields of individual USDA grades and total marketable yield were compared using a simple T-test (P<0.05) with the five locations used as blocks in a randomized complete block design.

Results and Discussion

The overall average percentage of fruits infested with ECB was significantly lower (1.1%) in the T.o. release plots than in the control plots (4.2%) when data from all locations were combined (Table 4). The same trend is obvious when the data were separated by production system (organic or conventional); there were approximately three times as many ECB-infested fruits in the control plots as in the release plots at the three conventional locations. There were approximately 10 times as many ECB-infested fruits in control plots as in release plots at the two organic sites (Table 4). However, given the limited error degrees of freedom available for comparing treatments within conventional or organic systems (df = 2 and 1, respectively), it is not surprising that these differences were not statistically significant. As might be expected given the low numbers of ECB this year at all five locations, there were no differences in marketable yields between control and release plots (Table 5).

Table 4. Average percentage of pepper fruits infested with one or more European corn borer larvae at five locations in Central Kentucky, 2002.
Treatment		Conventional Sites					Organic Sites			All Sites
		SF1	NF	SC	All Conv.		BC	KSU	All Organic
		% Infested Fruit
Control		4.7	2.2	8.0	5.0		0.8	5.1	3.0	4.2
Release		0.8	1.6	2.2	1.6		0.0	0.6	0.3	1.1
Significance		--	--	--	NS2		--	--	NS	*
1	SF = South Farm, NF = North Farm, SC = Scott County, BC = Berea College, KSU = Kentucky State University.
2	NS = non-significant.
*	Difference statistically significant by T test at P £ 0.05.

Table 5. Total marketable yields of control and release treatments for equivalent plot sizes at five locations in Central Kentucky, 2002.
Treatment		Conventional Sites					Organic Sites			All Sites
		SF1	NF	SC	All Conv.		BC	KSU	All Organic
		tons/acre
Control		13.4	14.5	5.4	11.1		3.0	5.6	4.3	8.4
Release		13.1	12.7	10.1	12.0		3.1	3.2	3.2	8.4
Significance		--	--	--	NS2		--	--	NS	NS
1	SF = South Farm, NF = North Farm, SC = Scott County, BC = Berea College, KSU = Kentucky State University.
2	NS = non-significant.

Numbers of ECB moths captured in pheromone traps have not yet been tabulated, as all identifications had not been completed at the time of this writing. Determination of percent parasitization of ECB sentinel egg masses has also not yet been completed.

European corn borer numbers were low at these five locations in Central Kentucky throughout the 2002 growing season as indicated by trap catches. Biological control of ECB in peppers using inundative releases of T.o. appears promising, at least when ECB infestations are low. This was the first year of a two-year study; next year we hope to include a site from northwestern Kentucky where larger ECB infestations are common in commercial pepper plantings.

Acknowledgments

The authors wish to greatly thank Darrell Slone, April Satanek, Philip Bush, and the UK Horticulture Farm summer workers for all of their hard work and wonderful assistance. Also thanks to Dr. John Snyder for analyses of the data. We would also like to thank the other institutions and individuals involved in this cooperative research, including Dr. Sean Clark at Berea College, Tony Silvernail at Kentucky State University, John Bell in Scott County, and Jeanette Dyer from the USDA lab at Iowa State University. This project is supported by a grant from the USDA's Cooperative State Research, Education, and Extension Service (CSREES).

Effects of Actigard on Tomato Yields

Amanda Ferguson, R. Terry Jones, John Snyder and William Nesmith, Departments of Horticulture and Plant Pathology

Introduction

Kentucky growers currently produce about 1,000 acres of staked vine-ripened tomatoes for both local and national markets. Kentucky tomatoes have an excellent reputation for quality in many market areas. During the past few years bacterial diseases (bacterial spot, speck, and canker) have become major concerns for many fresh market producers. The traditional spray program used by growers offers little in the way of control for these bacterial diseases. The emergence of bacterial diseases that are resistant to copper or streptomycin has complicated traditional control of bacterial diseases on tomatoes. All of these bacterial diseases can be seed-borne, and, with increased reliance on foreign production of hybrid seeds, the number of transplants carrying one or more of these diseases has increased. A new approach to disease control (plant immunity), Actigard, recently received a label for use on tomatoes.

Actigard, a plant activator, stimulates the plant's natural defense system, inducing systemic activated resistance (SAR) in the plant. This allows the plant to defend itself against fungal, bacterial, or viral attacks. The evolution of pathogens resistant to chemicals is all but inevitable. Already, some pathogens are resistant to our conventional chemical weapons, such as copper. By choosing a chemical that stimulates the plants' natural defense system, we may begin to win the battle against the rapidly evolving pathogens. Although it has been shown that Actigard can reduce the percentage of fruit and leaves infected, adequate research has not been done on the effects of Actigard on the horticultural and morphological characteristics of the tomato plant. It is reasonable to believe that since the plant is giving more of its overall energy to activating its immune system, less energy will be available for other plant functions (growth, fruit development). This could affect the size, shape, or number of the leaves, stems, or fruits.

We need to compare various disease management strategies to determine their impact on quality and yield. This research focused on measuring the effects of Actigard use on tomato fruit yield under Kentucky conditions.

Materials and Methods

Three different tomato cultivars, Cherry Grande, Heavy Weight, and Mountain Fresh were used. Cherry Grande is a 66-day, determinate, red cherry tomato cultivar. Heavy Weight is a 78-day, indeterminate, red-fruited cultivar, and Mountain Fresh is a 77-day, determinate, red-fruited cultivar that is commonly grown in Kentucky.

Tomato transplants were started in the greenhouse on 4 April 2001 and transplanted to the field on 5 May. Based on soil test results, 50 lb/A N and 100 lb/A K₂O fertilizer were applied preplant. An additional 75 lb of N and 50 lb of K₂O were applied during 10 weekly applications through the drip irrigation lines. Tomatoes were planted in rows 7 ft apart with plants spaced 18 inches apart in the row.

Tomato plants were treated with one of two spray regimes. The traditional regime consisted of a weekly spray program using alternating applications of mancozeb and Quadris early in the growing season, followed by weekly applications of Bravo plus fixed copper late in the season. A total of 13 applications were made. Fixed copper was added to the Bravo spray program because of the appearance of bacterial spot. The Actigard regime was the same as the traditional regime, plus it included six weekly applications of Actigard starting on 25 May, 16 days after the tomatoes were transplanted. The last application was made 27 June. The first two weekly applications consisted of one-third of an ounce Actigard 50WG in 50 gallons. One-half of an ounce in 70 gallons was applied during weeks three and four, and three-fourths of an ounce Actigard 50WG in 100 gallons was used for weeks five and six.

In addition to the weekly fungicide treatment, all plots received insecticides (Endosulfan 3EC or Pounce 3.2 EC ) as needed to control Colorado Potato Beetles or aphids.

Harvests began on 24 July and continued until 30 August for a total of nine or 10 harvests depending on the cultivar. Tomatoes were graded, counted, and weighed.

Results

For early yield of Cherry Grande, application of Actigard did not affect yield or fruit number (Tables 1 and 2) but did result in reduced yield (pounds and number) of jumbo/extra large and large Heavy Weight tomatoes compared to the traditionally treated controls. Interestingly, treatment with Actigard was associated with a reduction in pounds of Heavy Weight cull fruit. Early yields of jumbo/extra large Mountain Fresh fruit were also reduced in the Actigard treatment. Total early yields (Tables 1 and 2) were less when Actigard was applied to the Heavy Weight and the Mountain Fresh cultivars, compared to their traditionally treated controls. However, total yield of Cherry Grande was unaffected by Actigard application. Yields of medium and No. 2 fruit were unaffected by treatment with Actigard regardless of tomato cultivar. Differences in early yield between traditional treatment and the Actigard treatment were mainly related to differences in the size and number of large or extra large/jumbo fruit.

Table 1.Early yield in each grade category of three tomato cultivars, treated or not treated with Actigard, Quicksand, 2001.
Cultivar		Treatment1	No. 1 Jumbo + Extra Large2	No. 1 Large2	No. 1 Med + Small2	No. 22	Culls2	Total
			Pounds/A
Cherry Grande		T	-	9,231 ns	8,880 ns	3,799 ns	1,997 ns	23,906 ns
		T & A	-	9,827	7,869	3,630	1,854	23,180
Heavy Weight		T	12,990*	13,185*	9,373 ns	920 ns	5,315**	41,784*
		T & A	6,887	8,167	8,142	2,048	3,539	28,781
Mt. Fresh		T	19,343*	2,009 ns	363 ns	1,296 ns	1,245 ns	24,256*
		T & A	15,132	1,063	207	700	882	17,981
1	T = Traditional spray regime, T&A = Traditional spray regime plus Actigard; see Materials and Methods.
2	Jumbo fruit > = 3.5 in., Extra Large > = 2.75 but < 3.5 in., Large > = 2.5 but < 2.75, Medium < 2.5 in. The ns, *, and ** indicate a non-significant difference between the pair of means for a cultivar, a difference at P = 0.05 and 0.01, respectively. The means are least square means, compared by t-test. Preplanned comparisons were used.

Table 2. Number of fruit per acre in each grade category for the early harvests of three cultivars of tomato treated with Actigard or not treated, Quicksand, 2001.
Cultivar		Treatment1	No. 1 Jumbo + Extra Large2	No. 1 Large2	No. 1 Med + Small2	No. 22	Culls	Total
			Number of Fruit/A
Cherry Grande		T	0	38,763 ns	49,523 ns	21,910 ns	17,243 ns	127,439 ns
		T & A	0	42,782	40,449	19,187	14,779	117,197
Heavy Weight		T	30,985*	40,838*	43,041 ns	2,334 ns	21,650 ns	138,847*
		T & A	15,816	27,484	37,856	7,390	16,465	105,011
Mt. Fresh		T	32,540*	5,964 ns	1,426 ns	2,593 ns	3,371 ns	45,893 ns
		T & A	26,577	2,852	778	1,296	1,815	33,318
1	T = Traditional spray regime, T&A = Traditional spray regime plus Actigard; see Materials and Methods.
2	Jumbo fruit > = 3.5 in., Extra Large > = 2.75 but < 3.5 in., Large > = 2.5 but < 2.75, Medium < 2.5 in. The ns, *, and ** indicate a non-significant difference between the pair of means for a cultivar, a difference at P = 0.05 and 0.01, respectively. The means are least square means, compared by t-test. Preplanned comparisons were used.

Trends for total season yields (pounds and fruit number) were very different from those for early yield (Tables 3 and 4). Cherry Grande had a significant reduction in medium and small fruit numbers and pounds of medium/small tomatoes and a reduction in cull fruit numbers when Actigard was used, compared to the traditionally treated control. Application of Actigard on Heavy Weight tomato was associated with a severe reduction in pounds of large fruit and number of large and extra large/jumbo fruit, compared to its traditionally treated control. Pounds and number of cull fruit were reduced when Actigard was used on Heavy Weight. For Mountain Fresh total season yields, application of Actigard resulted in an increase in the pounds and number of extra large/jumbo tomatoes and a reduction in the pounds of cull tomato fruit.

Table 3. Total yield in each grade category of three tomato cultivars, treated or not treated with Actigard, Quicksand, 2001.
Cultivar		Treatment1	No. 1 Jumbo + Extra Large2	No. 1 Large2	No. 1 Med + Small2	No. 22	Culls	Total
			Pounds/A
Cherry Grande		T	0	23,362 ns	36,663**	4,615 ns	4,836 ns	69,476 ns
		T & A	0	25,695	33,098	4,719	3,656	67,167
Heavy Weight		T	21,521 ns	24,191*	28,353 ns	2,502 ns	9,542*	86,108*
		T & A	13,509	16,581	25,890	3,850	6,651	66,481
Mt. Fresh		T	59,428**	10,644 ns	2,437 ns	2,865 ns	3,228**	78,602 ns
		T & A	70,655	10,735	3,150	1,727	1,516	87,781
1	T = Traditional spray regime, T&A = Traditional spray regime plus Actigard; see Materials and Methods.
2	Jumbo fruit > = 3.5 in., Extra Large > = 2.75 but < 3.5 in., Large > = 2.5 but < 2.75, Medium < 2.5 in. The ns, *, and ** indicate a non-significant difference between the pair of means for a cultivar, a difference at P = 0.05 and 0.01 respectively. The means are least square means, compared by t-test. Preplanned comparisons were used.

Table 4.Number of fruit per acre in each grade category for entire season of three cultivars of tomato treated with Actigard or not treated, Quicksand, 2001.
Cultivar		Treatment1	No. 1 Jumbo + Extra Large2	No. 1 Large2	No. 1 Med + Small2	No. 22	Culls	Total
			Number of Fruit/A
Cherry Grande		T	0	105,400 ns	228,171*	27,873 ns	56,395*	417,839 ns
		T & A	0	116,419	198,613	27,613	37,078	379,724
Heavy Weight		T	51,875**	79,341**	146,756 ns	8,297 ns	51,728**	337,979**
		T & A	31,244	55,876	131,717	14,260	42,134	275,232
Mt. Fresh		T	106,955*	33,707 ns	12,057 ns	7,260 ns	12,316 ns	172,295 ns
		T & A	136,644	33,448	14,261	4,667	4,667	193,686
1	T = Traditional spray regime, T&A = Traditional spray regime plus Actigard; see Materials and Methods.
2	Jumbo fruit > = 3.5 in., Extra Large > = 2.75 but < 3.5 in., Large > = 2.5 but < 2.75, Medium < 2.5 in. The ns, *, and ** indicate a non-significant difference between the pair of means for a cultivar, a difference at P = 0.05 and 0.01 respectively. The means are least square means, compared by t-test. Preplanned comparisons were used.

There was an interaction between tomato cultivar and the spray treatment used. Compared to its traditionally treated control, Mountain Fresh treated with Actigard had a lower yield early in the season, but season-long total yield for the Actigard treatment was greater than its control. On the other hand, both early and total yield of Heavy Weight was reduced by application of Actigard. Cherry Grande early-season yields were not affected by the spray program, but for the full season, number and pounds of medium/small fruit and culls were reduced by Actigard application. In general, the application of Actigard reduced the number and pounds of cull fruit. This reduction was not associated with any obvious fruit disease. A late-season infection of bacterial leaf spot developed in the trial during harvest.

There was a significant difference between the three tomato cultivars in disease severity (Table 5). Mountain Fresh had less disease than the other two cultivars. Cherry Grande had significantly more. At the time of the first evaluation, the Mountain Fresh plants that had been treated with Actigard had significantly less disease than the traditionally treated Mountain Fresh plants (Table 6). Two weeks later, this difference had disappeared. The final traditional spray was applied to the tomatoes on 2 August. Actigard's effects on tomato fruit yield occurred prior to the development of the bacterial disease.

Table 5. Bacterial speck disease ratings on 31 August and 14 September for three tomato cultivars. Means are averages for tomato plants treated and not treated with Actigard.
Cultivar		Bacterial Speck Rating1
		31 August	14 September
Mt. Fresh		1.8c	2.1b
Heavy Weight		2.6b	2.1b
Cherry Grande		3.5a	4.4a
1	Bacterial speck was rated on 8/31/01 by T. Jones using a 0-5 scale: 0 = no speck, 5 = near total leaf coverage with spot. W. Nesmith rated on 9/14/01 using the same subjective scale. Means followed by the same letter are not significantly different, LSD (P = 0.05). The ratings were made 65 and 79 days after the last application of Actigard on June 27.

Table 6. Bacterial speck disease ratings for three varieties of tomato treated with Actigard or not treated.
Variety		Treatement2	Bacterial Speck Rating1
			31 August	14 September
Mt. Fresh		T	2.5bc	2.125b
		T&A	1.0d	2.0b
Heavyweight		T	3.0abc	2.125b
		T&A	2.25c	1.875b
Cherry Grande		T	3.75a	4.375a
		T&A	3.25ab	4.5a
1	Bacterial speck was rated on 31August by T. Jones using a 0-5 scale: 0 = no speck, 5 = near total leaf coverage with spot. W. Nesmith rated on 14 September using the same subjective scale. The ratings were made 65 and 79 days after the last application of Actigard on June 27. Means within a column followed by the same letter are not significantly different, LSD (P = 0.05).
2	T = Traditional spray regime, T&A = Traditional spray regime plus Actigard; see Materials and Methods.

Additional studies are needed: 1) to determine the effects of Actigard on the majority of tomato cultivars grown in Kentucky; 2) to determine the best timing of Actigard sprays; and 3) to determine the effects of location and time of year on Actigard application. There is no doubt that the use of Actigard can significantly reduce potential yield losses due to bacterial spot/speck epidemics. However, this protection may have a price associated with it. We recommend that growers practice sanitation and follow a recommended spray program in tomato transplant production. Tomato fields should be properly fertilized and rotated to reduce disease problems. Actigard, if used, should probably be applied biweekly, separate from other pest control applications. Thorough coverage with Actigard is not necessary, so spray volume/acre could be reduced.

Cover Crop Roll-Down for Weed Suppression in No-Till Crop Production

Sean Clark and Michael Panciera, Department of Agriculture and Natural Resources, Berea College

Introduction

No-till crop production has a number of advantages over conventional tillage, including improved soil moisture retention, reduced soil erosion, lower energy use, and reduced losses of soil organic matter. However, no-till agriculture as it is generally practiced, is dependent on herbicide use, which can lead to other problems, including groundwater and surface water contamination and risks to human health. Developing no-till methods that are not herbicide dependent will lead to cropping systems that not only protect soil resources but do so without the environmental and human health costs often associated with herbicide use.

Over the past decade, researchers and farmers in several states have been evaluating and improving cover crop management practices in no-till horticultural cropping systems (Teasdale and Abdul-Baki 1998, Morse 1999, Creamer and Dabney 2002, Abdul-Baki et al. 2002). Rolling down a mature winter cover crop in the spring and planting or transplanting directly into the mulch residue that is left on the surface has proven feasible and provides a variety of benefits. By rolling the cover crop down rather than mowing it, the cover crop residue breaks down more slowly, providing longer weed suppression by the mulch.

While cover crop roll-down has significant potential to make no-till farming less herbicide dependent and more profitable, there are several potential problems that need addressing. First, there is the possibility of cover crop re-growth after roll down that can result in serious, yield-limiting competition with the planted crop. Research and experience has shown that the timing of the roll-down relative to the maturity of the small grain and/or legume cover crop is critical for avoiding cover crop re-growth problems. In addition, the cover crop residue may not last long enough to provide sufficient weed control. Additional weed management practices may be needed, such as herbicide applications, cultivations, or flaming.

Materials and Methods

A field experiment was conducted at the educational farm of Berea College www.berea.edu/ANR/farms.htm to evaluate cover crop roll-down for field corn production. The experiment included three treatments with four replications. The treatments included:

1. Cover crop roll-down only (no herbicides).
2. Cover crop roll-down followed by an application of glyphosate (Roundup, 1 qt/A) at corn planting.
3. Cover crop roll-down followed by an application of glyphosate (Roundup, 1 qt/A) at corn planting and an application of dicamba (Banvel, 0.5 pt/A)* and primisulfuron-methyl (Beacon, 0.76 pt/A)* one month after planting.

Rye Winter King was planted as a winter cover crop in the entire field site on October 15, 2001, at 100 lb/A. On May 17, 2002, the rye was rolled down with a rolling stalk chopper when it reached the "soft dough" stage (Figure 1). At this time the total aboveground biomass of the rye was 2.4 T/A. Plots were established, each measuring 12.7 ft wide and 500 ft long (6,350 ft²), in a randomized block design.

Figure 1. Rolling down the rye cover crop using a rolling stalk chopper before corn planting, Berea, KY, 2002.

On May 22, corn Pioneer 33Y18 was planted at 19,600 seeds/A using a John Deere series 7000, four-row planter modified for high residues (fluted coulter, residue cleaners in front of unit, and spiked closing wheels) in 38-inch rows (Figure 2). Glyphosate was applied in a 12-inch band over the rows at planting in treatments 2 and 3 to suppress weeds and possible rye re-growth. On June 19, dicamba (Banvel, 0.5 pt/A) and primisulfuron-methyl (Beacon, 0.76 pt/A) were applied to treatment 3. Fertilizer (150 lb/A of N as urea and 45 lb/A of K as KCl) was applied to all plots on June 26.

Figure 2. The no-till corn planter was modified for high surface residues: fluted coulter, residue cleaners in front of seeding unit, and spiked closing wheels, Berea, KY, 2002.

Corn plant stand counts were made after planting to ensure equal stands in the three treatments. Corn and weed biomass were measured by field sampling when the corn reached the silking stage (July 22) to assess the effects of the herbicide treatments. At maturity, the corn was hand harvested to estimate grain yield (October 8). Net economic returns were calculated by subtracting total costs from gross returns (yields multiplied by price per bushel).

Results and Discussion

Corn plant populations were the same in all three treatments, approximately 20,000 plants per acre. Corn plant biomass at silking was significantly greater and weed biomass significantly lower in treatment 3, which received the two herbicide applications, compared to the other two treatments (Table 1). Treatments 1 and 2, however, did not differ from each other in corn or weed biomass at this time, indicating that the glyphosate application was not necessary for weed or cover crop suppression. There was little cover crop re-growth, and rye mulch effectively suppressed weeds early in the corn season.

Table 1. Average corn and weed above ground biomass (lb/A) at corn silking in the cover crop roll-down experiment, Berea, Kentucky, July 22, 2002.
Treatment		Biomass (lb/A)
		Corn	Weed	Total
1		4275 a*	2285 a	6560
2		4734 a	1871 a	6605
3		5505 b	868 b	6373
*	Means within columns with different letters are significantly different (Tukey test, P £ 0.05).

At maturity, no significant differences in corn grain yield were found among the three treatments, but treatment 3, which received the two herbicide applications, had the highest overall yield (Table 2). Treatment 1, which received no herbicide applications, had the greatest variability in yield across the replicates, but average grain yield in this treatment was approximately the same as that of treatment 2, which received glyphosate (Table 2).

Table 2. Average corn grain yield, cost of production, gross returns, and net returns for the three treatments in the cover crop roll-down experiment, Berea, Kentucky, October 8, 2002.
	Treatment
	1	2	3
Corn grain yield (bu/A)	127	121	144
Total cost of production ($/A)	200	204	232
Gross returns at $2.00/A ($/A)	254	242	288
Net returns at $2.00/A ($/A)	54	38	56
Gross returns at $2.50/A ($/A)	318	303	360
Net returns at $2.50/A ($/A)	118	99	128

All three treatments were profitable at corn prices ranging from $2.00 to $2.50 per bushel. The application of glyphosate at planting did not improve profitability, but the post-emergence herbicide application did improve profits slightly. Based on these findings, it appears a cover crop of rye rolled down before planting can provide effective weed control even without herbicide applications. In this study, the herbicide application one month after planting did contribute to slightly higher yields but did not improve profitability dramatically.

In conclusion, rolling down a winter cover crop of rye can provide very good weed suppression in no-till crop production systems, reducing or eliminating the need for herbicides. Although cover crops that are used as mulch will add to the costs of production, they may still increase profitability by suppressing weeds, reducing herbicide costs, and conserving soil moisture for the cash crop. Future studies will evaluate rye seeded at higher rates (e.g., 150 lb/A) to achieve greater biomass at roll-down for season-long weed suppression. In addition, the cover crop roll-down system will be evaluated for other crops including sweet corn, squash, pumpkins, and tomatoes. By incorporating hairy vetch into a mixture with rye, N fertilizer needs may be reduced as well.

Acknowledgments

Bob Harned, Justin Ranck, Jason Hughes, Amanda Richie, Faye Tewksbury, Wendell Garnett, Anna Armstrong, Beth Perkins, Denis Burton, and Casey Babb contributed in various ways to this field study, including planting and data collection.

References Cited

Abdul-Baki, A.A., J.R. Teasdale, R.W. Goth, and K.G. Haynes. 2002. Marketable yields of fresh-market tomatoes grown in plastic and hairy vetch mulches. HortScience 37: 878-881.

Creamer, N.G. and S.M. Dabney. 2002. Killing cover crops mechanically: Review of recent literature and assessment of new research results. American Journal of Alternative Agriculture 17: 32-40.

Morse, R.D. 1999. No-till vegetable production - its time is now. HortTechnology 9: 373-379.

Teasdale, J.R. and A.A. Abdul-Baki. 1998. Comparisons of mixtures vs. monocultures of cover crops for fresh-market tomato production with and without herbicide. HortScience 33: 1163-1166.

*For field corn only; neither Banvel nor Beacon are labeled for use on sweet corn.

Fruit and Vegetable Disease Observations from the Plant Disease Diagnostic Laboratory

Julie Beale, Paul Bachi, William Nesmith, and John Hartman, Department of Plant Pathology

Introduction

Diagnosis of plant diseases and providing recommendations for their control are the result of UK College of Agriculture research (Agricultural Experiment Station) and Cooperative Extension Service activities through the Department of Plant Pathology. We maintain two branches of the Plant Disease Diagnostic Laboratory, one on the UK campus in Lexington, and one at the UK Research and Education Center in Princeton. Of the more than 4,000 plant specimens examined annually, approximately 10% to 15% are commercial fruit and vegetable plant specimens (1). The annual number of commercial fruit and vegetable specimens diagnosed has more than doubled in recent years, but, because of their complexity and diversity, the time needed to diagnose them has more than doubled. Although there is no charge to the growers for plant disease diagnosis at UK, the estimated direct annual expenditure to support diagnosis of fruit and vegetable specimens by the laboratory is $25,000, excluding UK physical plant overhead costs.

Materials and Methods

Diagnosing fruit and vegetable diseases involves a great deal of research into the possible causes of the problem. Most visual diagnoses include microscopy to determine what plant parts are affected and to identify the microbe involved. In addition, many specimens require special tests such as moist chamber incubation, culturing, enzyme-linked immunosorbent assay (ELISA), electron microscopy, nematode extraction, or soil pH and soluble salts tests. Diagnoses which require consultation with UK faculty plant pathologists and horticulturists, and which need culturing and ELISA, are common for commercial fruits and vegetables. The laboratory also has a role in monitoring pathogen resistance to fungicides and bactericides. These exceptional measures are efforts well-spent because fruits and vegetables are high-value crops for Kentucky. Computer-based laboratory records are maintained to provide information used for conducting plant disease surveys, identifying new disease outbreaks, and formulating educational programs.

The 2002 season had an unusually warm fall (2001) and mild winter. January temperatures were 7° to 10°F above normal and reached 60° to 70°F, causing some buds to swell. On March 4, temperatures dropped into the single digits (4° to 6°F), and on March 22 temperatures dropped into the mid-teens. Many peach buds and the king bloom on some apple varieties were lost in a number of orchards. On May 19, a particularly late freeze occurred that killed more peach and apple blooms. The late freeze was particularly hard on grapes in low-lying areas, which had made extensive growth by this time. Extremely warm temperatures in April favored severe fire blight in the central and eastern portions of the state.

Statewide, wet weather generally prevailed in March, April, and May, but dry weather was prevalent during June, July, and August. Rain was spotty, and some locales suffered severe drought, while others suffered only moderate drought. One grower in the Owensboro area reported 120 days without rain. Summer temperatures were above normal in addition to being dry.

Results and Discussion

New and Emerging Fruit and Vegetable Diseases in Kentucky

• Pierce's disease of grapes caused by Xylella fastidiosa.
• Grape crown gall caused by Agrobacterium tumefaciens emerges with more grapes grown.
• Cucurbit yellow vine decline caused by Serratia marsescens.
• Root, stem, and fruit diseases of solanaceous and cucurbit vegetables caused by Phytophthora spp.
• Bacterial canker of peppers caused by Clavibacter michiganensis subsp. michiganensis.
• Copper-resistant bacterial speck of tomatoes caused by Pseudomonas syringae pv. tomato.

Tree Fruit Diseases

Rain and long periods of spring leaf wetness increased the occurrence of primary infections of apple scab (Venturia inaequalis) and cedar rust (Gymnosporangium juniperi-virginianae, G. clavipes, and G. globosum). Periodically mild spring weather and showers during apple and pear bloom resulted in significant fire blight (Erwinia amylovora) in those areas of the state where bloom, warm weather, and rain coincided. Some Asian pears were hard hit. Spring frosts occurred and may have exacerbated fire blight. Spring rains also favored apple frogeye leaf spot (Sphaeropsis malorum). Dry summer weather reduced incidence of secondary apple scab and apple sooty blotch (Peltaster fructicola, Geastrumia polystigmatis, Leptodontium elatius, and other fungi) and flyspeck (Zygophiala jamaicensis), all of which are enhanced by long leaf wetness periods. Bitter rot (Colletotrichum gloeosporioides) was found in some apple orchards. Apple southern blight (Sclerotium rolfsii) was found in a newly planted orchard.

Winter and spring freezes resulted in some tree fruit injury that could have exacerbated stone fruit Cytospora (Leucostoma persoonii) cankers. As leaves emerged, peach leaf curl disease (Taphrina deformans) appeared. Spring rains favored peach scab (Cladosporium carpophilum) bacterial canker (Pseudomonas mors-prunorum), bacterial leaf spot (Xanthomonas campestris pv. pruni), and brown rot (Monilinia fructicola).

Small Fruit Diseases

Greenhouse strawberries were subject to powdery mildew (Sphaerotheca macularis f.sp. fragarae), and in the field strawberry leaf spot (Mycosphaerella fragariae) was common. In brambles, systemic orange rust (Gymnoconia nitens) and blackberry rosette (Cercosporella rubi) were frequently observed. Grape crown gall (Agrobacterium tumefaciens) continues to be a very serious problem for growers. Wet spring weather favored black rot (Guignardia bidwellii) and anthracnose (Elsinoe ampelina). Several cases of grape downy mildew (Plasmopara viticola) were observed. Pierce's disease (Xylella fastidiosa) in western Kentucky was confirmed. Summer air stagnation caused ozone injury to many plants and was especially noticeable on grapes.

Vegetable Diseases

In accord with a wet spring and hot, dry summer in many areas of the state, infectious diseases played a significant role in successful production of commercial vegetable crops.

Vegetable Transplants. Several diseases were diagnosed from vegetable transplant production within the state, including: Pythium root rot (Pythium sp.) of tomato, pepper, broccoli, and cantaloupe seedlings and transplants. Pythium root rot was diagnosed mainly from transplant operations involving the float system. Pepper transplants with gray mold blight (Botrytis cinerea) were also observed.

Cole Crops. Bacterial soft rot (Erwinia carotovora) was observed on cabbage. This disease sometimes follows infection by black rot (Xanthomonas campestris) bacteria. Another disease diagnosed included wirestem (Rhizoctonia solani) on transplants and newly set cole crops, including cabbage, and cauliflower, plus the fungus caused stem and head rots later in the season.

Tomatoes. Commercial tomato plantings were infected by several bacterial diseases including bacterial canker (Clavibacter michiganensis), bacterial spot (Xanthomonas campestris pv. vesicatoria), and bacterial speck (Pseudomonas syringae pv. tomato). Pythium root rot from the transplants carried over into the field. Two fungal leaf spots, early blight (Alternaria solani), and Septoria leaf spot (Septoria lycopersici), and two fruit rots, buckeye rot (Phytophthora cactorum), and blossom end rot also occurred. Other fruit diseases included the fungal and bacterial leaf diseases listed above. Tomato fruit also experienced a number of other physiological disorders such as catfacing, growth cracks, yellow shoulders, and sunscald. Fusarium wilt (Fusarium oxysporum f.sp. lycopercici), timber rot (Sclerotinia sclerotiorum), southern blight (Sclerotium rolfsii), and root knot nematode (Meloydogyne incognita) were problems in some fields. A number of viral diseases caused losses associated with TSWV (Tomato Spotted Wilt Virus) and ToMV/TMV (Tomato Mosaic Virus/Tobacco Mosaic).

Peppers. Bacterial leaf spot (Xanthomonas campestris pv. vesicatoria) remains an important problem. Important virus diseases of pepper included pepper mottle and TSWV (tomato spotted wilt virus). Occasionally, southern stem blight (Sclerotium rolfsii) and stem rot (Rhizoctonia solani) were problems. Pythium root rot (Pythium spp.) was found, especially where associated with already infected transplants.

Cucurbits. Cucurbits are becoming more popular in Kentucky, and their diseases are increasing in economic importance. Phytophthora root rot, stem rot, leaf blight and fruit rot (Phytophthora capsici) is widespread in the state and causes losses in many fields of pumpkins, squash, and cucumbers. Microdochium blight (Microdochium sp. recently renamed Plectosporium) caused some damage in some fields that were not being sprayed well; the causes of poor spraying, even if being sprayed regularly, are poor timing, poor coverage, or use of the wrong fungicides. Watermelon and squash showed, respectively, Fusarium root rot and root and crown rot (Fusarium spp.) diseases. Nutritional disorders were also common, including several cases of manganese toxicity and blossom end rot. Anthrancnose (Colletotrichum spp.), gummy stem blight/black rot (Mycosphaerella melonis), and Cercospora leaf spot (Cercospora melonis) were found at serious levels in some fields on many of the cucurbits. The potyvirus complex, dominated by Watermelon Mosaic Virus 2, was widespread in pumpkin and winter squash, while several cases of Cucumber Mosaic Virus were also found in melon crops. Bacterial diseases of cucurbits included angular leaf spot (Pseudomonas syringae pv. lachrymans) and bacterial wilt (Erwinia tracheiphila). Symptoms of a newly emerging bacterial disease, Cucurbit Yellow Vine Decline caused by Serratia marsescens, were found in watermelon, muskmelon, summer squash, and winter squash.

Other Vegetables. Bean root and stem rot (Pythium spp., Rhizoctonia solani and Fusarium solani f.sp. phaseoli), bean anthracnose (Colletotrichum lindemuthianum), and pea stem rot (Rhizoctonia solani) were observed this year. Dry rot (Fusarium sp.) occurred on potato tubers.

Growers are urged to bring to the attention of their County Extension Agent any observations of new outbreaks and disease trends in their fields. We want to be especially watchful of the new spectrum of microbes and diseases that may occur with changes in fungicide use patterns from broad-spectrum protectant fungicides such as mancozeb and chlorothalonil to new chemicals such as Quadris and Abound, which present a greater risk of pathogen resistance to the fungicide while incurring reduced risks to human health and the environment. For example, we have noted increased bacterial diseases in tomatoes and now want to know if this is due to how we raise our crops, manage other diseases, or import seeds and transplants.

Because fruits and vegetables are high-value crops, the Plant Disease Diagnostic Laboratory should be a great value to commercial growers. However, many growers are not using this laboratory often enough or they are waiting until their disease problem has become well established. By then, it may be too late to do anything about it, or in some cases to correctly diagnose the sequence of diseases that may have led to the final outcome. Growers need to consult consistently with their County Extension Agents so that appropriate plant specimens are sent to the laboratory in a timely manner. We are urging County Extension Agents to stress in their Extension programming the need for accurate diagnosis of diseases of high-value crops. Growers can work with their agents to see that Kentucky growers have the best possible information on fruit and vegetable diseases.

Literature Cited

1. Bachi, P.R., J.W. Beale, J.R. Hartman, D.E. Hershman, W.C. Nesmith, and P.C. Vincelli. 2003. Plant Diseases in Kentucky—Plant Disease Diagnostic Laboratory Summary, 2002. UK Department of Plant Pathology (in press).

Appendix A: Sources of Vegetable Seeds

We would like to express our appreciation to these companies for providing seeds at no charge for vegetable variety trials.

The abbreviations used in this appendix correspond to those listed after the variety names in tables of individual trial reports.

AAS: All America Selection Trials, 1311 Butterfield Road, Suite 310, Downers Grove, IL 60515

AS/ASG: Formerly Asgrow Seed Co., now Seminis (see "S" below)

AC: Abbott and Cobb Inc., Box 307, Feasterville, PA 19047

AG: Agway Inc., P.O. Box 1333, Syracuse, NY 13201

AM: American Sunmelon, P.O. Box 153, Hinton, OK 73047

AR: Aristogenes Inc., 23723 Fargo Road, Parma, ID 83660

AT: American Takii Inc., 301 Natividad Road, Salinas, CA 93906

BBS: Baer's Best Seed, 154 Green St., Reading, MA 01867

BK: Bakker Brothers of Idaho Inc., P.O. Box 1964, Twin Falls, ID 83303

BR: Bruinsma Seeds B.V., P.O. Box 1463, High River, Alberta, Canada, TOL 1B0

BS: Bodger Seed Ltd., 1800 North Tyler Ave., South El Monte, CA 91733

BU: W. Atlee Burpee & Co., P.O. Box 6929, Philadelphia, PA 19132

BZ: Bejo Zaden B.V., 1722 ZG Noordscharwoude, P.O. Box 9, the Netherlands

CA: Castle Inc., 190 Mast St., Morgan Hill, CA 95037

CH: Alf Christianson, P.O. Box 98, Mt. Vernon, WA 98273

CIRT: Campbell Inst. for Res. and Tech., P-152 R5 Rd 12, Napoleon, OH 43545

CL: Clause Semences Professionnelles, 100 Breen Road, San Juan Bautista, CA 95045

CN: Canners Seed Corp., (Nunhems) Lewisville, ID 83431

CR: Crookham Co., P.O. Box 520, Caldwell, ID 83605

CS: Chesmore Seed Co., P.O. Box 8368, St. Joseph, MO 64508

D: Daehnfeldt Inc., P.O. Box 947, Albany, OR 97321

DN: Denholm Seeds, P.O. Box 1150, Lompoc, CA 93438-1150

DR: DeRuiter Seeds Inc., P.O. Box 20228, Columbus, OH 43320

EB: Ernest Benery, P.O. Box 1127, Muenden, Germany

EX: Express Seed, 300 Artino Drive, Oberlin, OH 44074

EZ: ENZA Zaden, P.O. Box 7, 1600 AA, Enkhuisen, Netherlands 02280-15844

FM: Ferry-Morse Seed Co., P.O. Box 4938, Modesto, CA 95352

G: German Seeds Inc., Box 398, Smithport, PA 16749-9990

GB: Green Barn Seed, 18855 Park Ave., Deephaven, MN 55391

GL: Gloeckner, 15 East 26th St., New York, NY 10010

GO: Goldsmith Seeds Inc., 2280 Hecker Pass Highway, P.O. Box 1349, Gilroy, CA 95020

HL/HOL: Hollar & Co. Inc., P.O. Box 106, Rocky Ford, CO 81067

H/HM: Harris Moran Seed Co., 3670 Buffalo Rd., Rochester, NY 14624, Ph: (716) 442-0424

HN: HungNong Seed America Inc., 3065 Pacheco Pass Hwy., Gilroy, CA 95020

HO: Holmes Seed Co., 2125-46th St., N.W., Canton, OH 44709

HZ: Hazera Seed Ltd., P.O.B. 1565, Haifa, Israel

JU: J. W. Jung Seed Co., 335 High St., Randolf, WI 53957

JS/JSS: Johnny's Selected Seeds, Foss Hill Road, Albion, ME 04910-9731

KS Krummrey & Sons Inc., P.O. 158, Stockbridge, MI 49285

KY: Known-You Seed Co. Ltd. 26 Chung Cheng Second Rd., Kaohsiung, Taiwan, R.O.C. 07-2919106

LI: Liberty Seed, P.O. Box 806, New Philadelphia, OH 44663

MB: Malmborg's Inc., 5120 N. Lilac Dr. Brooklyn Center, MN 55429

MK: Mikado Seed Growers Co. Ltd., 1208 Hoshikuki, Chiba City 280, Japan 0472 65-4847

ML: J. Mollema & Sons Inc., Grand Rapids, MI 49507

MM: MarketMore Inc., 4305 32nd St. W., Bradenton, FL 34205

MN: Dr. Dave Davis, U of MN Hort Dept., 305 Alderman Hall, St. Paul, MN 55108

MR: Martin Rispins & Son Inc., 3332 Ridge Rd., P.O. Box 5, Lansing, IL 60438

MS: Musser Seed Co. Inc., Twin Falls, ID 83301

MWS: Midwestern Seed Growers, 10559 Lackman Road, Lenexa, Kansas 66219

NE: Neuman Seed Co., 202 E. Main St., P.O. Box 1530, El Centro, CA 92244

NI: Clark Nicklow, Box 457, Ashland, MA 01721

NU: Nunhems (see Canners Seed Corp.)

NZ: Nickerson-Zwaan, P.O. Box 19, 2990 AA Barendrecht, Netherlands

OE: Ohlsens-Enke, NY Munkegard, DK-2630, Taastrup, Denmark

OS: L.L. Olds Seed Co., P.O. Box 7790, Madison, WI 53707-7790

P: Pacific Seed Production Co., P.O. Box 947, Albany, OR 97321

PA/PK: Park Seed Co., 1 Parkton Ave., Greenwood, SC 29647-0002

PE: Peter-Edward Seed Co. Inc., 302 South Center St., Eustis, FL 32726

PG: The Pepper Gal, P.O. Box 23006, Ft. Lauderdale, FL 33307-3006

PL: Pure Line Seeds Inc., Box 8866, Moscow, ID

PM: Pan American Seed Company, P.O. Box 438, West Chicago, IL 60185

PR: Pepper Research Inc., 980 SE 4 St., Belle Glade, FL 33430

PS: Petoseed Co. Inc., P.O. Box 4206, Saticoy, CA 93004

R: Reed's Seeds, R.D. #2, Virgil Road, S. Cortland, NY 13045

RB/ROB: Robson Seed Farms, P.O. Box 270, Hall, NY 14463

RC: Rio Colorado Seeds Inc., 47801 Gila Ridge Rd., Yuma, AZ 85365

RG: Rogers Seed Co., P.O. Box 4727, Boise, ID 83711-4727

RI/RIS: Rispens Seeds Inc., 3332 Ridge Rd., P.O. Box 5, Lansing, IL 60438

RS: Royal Sluis, 1293 Harkins Road, Salinas, CA 93901

RU/RP/RUP: Rupp Seeds Inc., 17919 Co. Rd. B, Wauseon, OH 43567

S: Seminis Inc. (may include former Asgrow and Peto cultivars), 2700 Camino del Sol, Oxnard, California 93030-7967

SI: Siegers Seed Co., 8265 Felch St., Zeeland, MI 49464-9503

SK: Sakata Seed America Inc., P.O. Box 880, Morgan Hill, CA 95038

ST: Stokes Seeds Inc., 737 Main St., Box 548, Buffalo, NY 14240

SU/SS: Sunseeds, 18640 Sutter Blvd., P.O. Box 2078, Morgan Hill, CA 95038

SW: Seedway Inc., 1225 Zeager Rd., Elizabethtown, PA 17022

T/TR: Territorial Seed Company, P.O. Box 158, Cottage Grove, OR 97424

TGS: Tomato Growers Supply Co., P.O. Box 2237, Ft. Myers, FL 33902

TS: Tokita Seed Company Ltd., Nakagawa, Omiya-shi, Saitama-ken 300, Japan

TT: Totally Tomatoes, P.O. Box 1626, Augusta, GA 30903

TW: Twilley Seeds Co. Inc., P.O. Box 65, Trevose, PA 19047

UG: United Genetics, 8000 Fairview Road, Hollister CA 95023

US: US Seedless, 12812 Westbrook Dr., Fairfax, VA 22030

V: Vesey's Seed Limited, York, Prince Edward Island, Canada

VL: Vilmorin Inc., 6104 Yorkshire Ter., Bethesda, MD 20814

VS: Vaughans Seed Co., 5300 Katrine Ave., Downers Grove, IL 60515-4095

VTR: VTR Seeds, P.O. Box 2392, Hollister, CA 95024

WI: Willhite Seed Co., P.O. Box 23, Poolville, TX 76076

ZR: Zeraim Seed Growers Company Ltd., P.O. Box 103, Gedera 70 700, Israel