edited by Brent Rowell
Faculty, Staff, Grower, and Industry Cooperators
Horticulture
FACULTY
Jerry Brown
Terry Jones
Brent Rowell
John Snyder
John Strang
TECHNICAL STAFF
June Johnston
Dave Lowry
Kay Oakley
Janet Pfeiffer
April Satanek
Dave Spalding
Darrell Slone
Richard Thacker
William Turner
Dwight Wolfe
Entomology
FACULTY
Ric Bessin
TECHNICAL STAFF
Kerry Kirk
Plant Pathology
John Hartman
Bill Nesmith
TECHNICAL STAFF
Paul Bachi
Julie Beale
Agronomy
FACULTY
David Ditsch
Animal Sciences
FACULTY
Joe O'Leary
Cooperative Extension
Service
EXTENSION AGENT FOR HORTICULTURE
Tom Brass (Henderson County)
Grower and Industry Cooperators
Bill Papania
Joe O'Leary
Robert Mitchell
Charles Mulligan
Demonstration Cooperators
Joe York
Tim Pope
Butch Case
Clarence Murphy
Ben Cambell
Jefferson Calico
Greg Young
Donnie Coulter
John Wilhoit
Jimmy Roberts
Glen Abney
Scott Essex
This is a progress report and may not reflect exactly the final outcome of ongoing projects.
Mention or display of a trademark, proprietary product, or firm in text or figures does not constitute an endorsement and does not imply approval to the exclusion of other suitable products or firms.
Dewayne Ingram, Chair, Department of Horticulture
The faculty, staff and students in the University of Kentucky's vegetable and fruit program are pleased to offer the 2000 Fruit and Vegetable Crops Research Report. This report is one way we share information generated from a coordinated research program involving contributions from several departments in the UK College of Agriculture. The University of Kentucky is your primary land-grant university and as such, our interdisciplinary teams of faculty, staff, and students focus their efforts on the complex needs and opportunities facing fruit and vegetable growers in the state. The research areas on which we concentrate reflect stated industry needs, expertise available at UK, and the nature of research programs in neighboring states and around the world that generate information applicable to Kentucky. If you have questions and/or suggestions about a particular research project, please do not hesitate to contact us.
Although the purpose of this publication is to report research results, please find below some highlights of how our Extension program and undergraduate and graduate degree programs are this year addressing the needs of the fruit and vegetable industries.
Extension programs targeted to Kentucky's fruit and vegetable industries include highly visible activities and some more subtle ones. The statewide and area educational conferences and seminars and the on-farm demonstrations shown during twilight farm tours are probably the most visible. Print publications, Web documents, videos, slide sets, newsletters, magazine articles, newspaper articles, radio spots, and television programs are important, visible elements of our Extension program. Activities that you may not see, however, are things like the horticultural training programs for county Extension agents, the work of the UK Plant Disease Diagnostic Laboratory, and soil testing and interpretative services.
Although many facets of the Extension program are conducted by the team of subject matter specialists and county agents, this year we would like to highlight the work of county Extension agents for horticulture.
The number of positions for county Extension agents for horticulture has increased from three to 17 in the last decade, due to the significant demand for horticulture educational programs at the county level. Each of the 120 counties have Extension agents for the program areas of Agriculture, Family and Consumer Sciences, and 4-H/Youth Development that are cooperatively funded by state, county and federal funds.
Additional agents, such as those specializing in horticulture, are funded entirely by the county. The horticulture agents are primarily located in counties with a large population center and target a major portion of their programming to consumers, mainly homeowners. A portion of their time is invested in the educational programs and service support for commercial horticultural industries. Although the size of each horticultural commodity and educational opportunities differ among counties, at least one segment of the commercial horticulture industry is important in each of these counties.
It is important to note that the county Extension agents for horticulture are part of the team of faculty, staff, agents, and students addressing horticultural opportunities through education and research. While much of their efforts is geared toward home horticulture, many of these individuals have had vital impact on commercial fruit and vegetable industries in their counties. You will see many of them working at the fruit and vegetable crops winter meeting and other events. However, I wanted to introduce them to you again here. They are:
Boone County Michael Klahr
The department offers areas of emphasis in horticultural enterprise management and horticultural science within a plant and soil science B.S. degree. The plant and soil science degree program had over 110 students in the fall semester of 2000, of which almost one-half were horticulture students and another one-third were turfgrass students. Six horticulture students graduated in 2000.
We believe that a significant portion of an undergraduate education in horticulture must come outside the classroom. In addition to the local activities of the UK Horticulture Club and field trips during course laboratories, students have excellent off-campus learning experiences. Here are the highlights of such opportunities in 2000:
A complete list of students and student activities can be viewed at <http://www.uky.edu/StudentOrgs/Horticulture>.
The demand is high for graduates with M.S. or Ph.D. degrees in horticulture, entomology, plant pathology, agricultural economics, and agricultural engineering. Our M.S. graduates are being employed in the industry, the Cooperative Extension Service, secondary and postsecondary education, and governmental agencies. Graduate students contribute significantly to our ability to address problems and opportunities important to the Kentucky fruit and vegetable industries.
Brent Rowell, Extension Vegetable Specialist
This publication, 2000 Fruit and Vegetable Crops Research Report, highlights results from the past year's variety trials and other research projects in Kentucky, including those for bacterial spot resistant bell peppers, hot and specialty peppers, sweet corn, blueberries, hard squash, and seedless watermelon as well as a cucumber beetle control trial in muskmelons, apple tree pruning method comparisons, and results of our on-farm demonstration program with tobacco growers.
An ongoing variety testing program producing reliable results in at least three major geographic regions of the state is needed just to preserve existing levels of competitiveness and development of the vegetable and other horticultural industries in Kentucky. We are doing only a fair job of vegetable crops research compared with other states in the region. For example, at this point in time there is no vegetable variety testing program west of Lexington in spite of the formation of significant new growers' associations in the western half of the state. There have been serious cuts in support staff and facilities available to conduct variety testing at each of the three research farms (Lexington, Quicksand, Princeton). We are presently making do with temporary employees paid for by temporary federal grant money.
It is unfortunate that Kentucky has been unwilling to step up to the plate and make the public investments required to support the type of applied, "low-tech" research described above, which is not pie-in-the-sky research conducted from an ivory tower. We simply want to do enough to enable growers to make a good living in farming. And to do that, we must keep abreast of new varieties, new sources of resistance to pests, new crops for niche markets, and new production techniques especially true given today's competitive, complex, and rapidly changing marketplace.
But like a ripe melon, the hope that Phase I tobacco settlement funds might be used to build an adequate applied research infrastructure in horticulture1 appears to have a brief shelf life. While an "entrepreneurship center" and other needed marketing initiatives will be funded, it appears considerably less likely that something will be done to ensure the establishment of an adequate support system of targeted horticultural research and Extension efforts.
Horticultural crops in general and vegetable crops in particular are the front line crops that most tobacco growers turn to first when they consider alternative crops. Little is being done to ensure that the requisite personal help and relevant information will be available for the flood of Kentucky's new horticultural entrepreneurs.
While it is still possible to drive our Model A Ford on many Kentucky backroads, it could prove difficult keeping up with the SUVs as we move onto the interstate highways of regional and national produce markets.
1 See Tomato Saviors, Silver Bullets, and Tobacco Alternatives, pp. 7-10 in Fruit and Vegetable Crop Research Report 1999, University of Kentucky (publication PR-423).
Brent Rowell
The 2000 Fruit and Vegetable Crops Research Report includes results of 16 field trials that were conducted at four locations in Kentucky (see map, below). The research was conducted by faculty and staff from several departments within the University of Kentucky College of Agriculture, including Horticulture, Entomology, and Plant Pathology. Most of these reports are of crop variety (cultivar) trials.
Growers usually put variety trials at the top of the list when rating projects at a public institution's research station. These trials provide a wealth of information not only to growers, but also to Extension agents, researchers, and seed companies. The reports also provide us with much of the information we need in order to include varieties in our Vegetable Production Guide for Commercial Growers (ID-36).
The main purpose of variety evaluation is to provide growers with practical information to assist them in selecting the most suitable variety for a given location or market. Here are some guidelines for interpreting the results of fruit and vegetable variety trials:
Yields reported in variety trial results are extrapolated from small plots. Depending on the crop, our trial plot sizes range anywhere from 50 to 500 square ft. Yields per acre are calculated by multiplying these small plot yields by correction factors ranging from 100 to 1,000. These yields per acre may not be realistic, and small errors can be amplified when correction factors are used. For example, the calculations may overestimate yields because the plots harvested do not include empty spaces normally occupied by things such as drive rows in a grower's field. These empty spaces may result in a higher per acre yield from the research plots compared to a grower's yield.
In some cases research plots may be harvested more often than is economically feasible in a grower's field. So, don't feel inadequate if our yields are higher than yours. You should be concerned, however, if our yields are lower than yours. In that case there may be good reason to suspect that the trial was conducted improperly.
It is not advisable to compare the yield of a variety at one location to the yield of a different variety at another location. The differences in performance among all varieties grown at the same location, however, can and should be used to identify the best varieties for growers nearest that locality. Results vary widely from one location or geographical region to another; a variety may perform well in one location and poorly in another for many reasons. Different locations may have different climates, microclimates, soil types, fertility regimes, and pest problems. Different trials at different locations are also subject to differing management practices. Only a select few varieties seem to perform well over a wide range of environmental conditions, and these varieties usually become the top-sellers.
Climatic conditions obviously differ considerably from one season to the next, and it follows that some varieties perform well one year and perform poorly the next. For this reason we prefer to have at least two years of trial data before coming to any hard and fast conclusions about a variety's performance. In other cases we may conduct a preliminary trial to eliminate the worst varieties while letting growers make the final choices regarding the best varieties for their farm and market conditions (see Rapid Action Cultivar Evaluation [RACE] trial description on page 8).
Most of the trial results reported here use statistical techniques to determine if there are any real (vs. accidental) differences in performance among varieties or treatments. Statistical jargon is often a source of confusion, and we hope this discussion will help. In many cases our trials are replicated, which simply means that instead of taking data from only one plot from one spot in the trial field, we plant that variety (or repeat the spray or fertilizer treatments) in other small plots in several spots in a field. If we test 20 pepper varieties, for example, we will have a small plot for each variety (20 separate plots) and then repeat this planting in two or three additional sets of 20 plots in the same trial field. These repeated sets of the same varieties are called replications, or blocks. The result is a trial field with 20 varieties x 4 replications = 80 small plots. The yield for a variety is reported as the average (also called the mean) of yields from the four separate small plots of that variety. The average per acre yields reported in the tables are calculated by multiplying these average small plot yields by a correction factor.
In most reports we list the results in tables with varieties ranked from highest to lowest yielding (see Table 1 on page 24.) Small differences in yield are often of little importance, and it is sometimes difficult to separate differences due to chance or error from actual differences in performance of varieties. The last line at the bottom of most data tables will usually contain a number that is labeled LSD, or Waller-Duncan LSD. LSD is a statistical measure that stands for "Least Significant Difference."
The LSD is the minimum yield difference that is required between two varieties before we can conclude that one actually performed better than another. This number enables us to separate real differences among the varieties from chance differences. When the difference in yields of two varieties is less than the LSD value, we can't say with any certainty that there's any real yield difference. In other words, we conclude that the yields are the same. For example, in the table on page 24 cited above, variety `Consul' yielded 32 tons per acre and `Boynton Bell' yielded 30 tons per acre. Since the difference in their yields (32-30 = 2 tons per acre) is less than the LSD value of 4.5 tons per acre, there was no real difference between these two yields. The difference between `Consul' and `Legionnaire' (32-26 = 6), however, is greater than the LSD, indicating that the difference between the yields of these two varieties is real.
Sometimes these calculations have already been made, and statistical comparisons among varieties are indicated by one or more letters (a, b, c, etc.) listed after the yields in the tables (see Table 2 on page 25). If yields of two varieties are followed by one or more of the same letters, they are considered to be identical (statistically speaking, that is). Yields of two varieties are different if they have no letters in common. In this example, the AUDPC values of `X3R Ironsides' and `X3R Chalice' are both followed by an `a,' so they are not different, while values for `X3R Ironsides' and `Crusader' have no letters in common, indicating that the difference between them is real (that is, statistically significant).
What is most important to growers is to identify the best varieties in a trial. What we usually recommend is that you identify a group of best performing varieties rather than a single variety. This is easily accomplished for yields by subtracting the LSD from the yield of the top-yielding variety in the trial. Varieties in the table having yields equal to or greater than the result of this calculation will belong in the group of highest yielding varieties. If we take the highest yielding pepper variety, `RPP 6088', in Table 1 (page 24) and subtract the LSD from its yield (32.1- 4.5 = 27.6), this means that any variety yielding 27.6 tons per acre or more will not be statistically different from `RPP 6088.' The group of highest yielding varieties in this case will include the 15 varieties from `RPP 6088' down the column through variety `X3R Red Knight.'
In some cases there may be a large difference between the yields of two varieties, but this difference is not real (not statistically significant) according to the statistical procedure used. Such a difference can be due to random chance, but often it occurs if there is a lot of variability in the trial. An insect infestation, for example, could affect only those varieties nearest the field's edge where the infestation began.
It is also true that our customary standard for declaring a statistically significant difference is quite high, or stringent. Most of the trial reports use a standard of 95% probability (expressed in the tables together with the LSD as P< 0.05 or P = 0.05). This means that there is a 95% probability that the difference between two yields is real and not due to chance or error. When many varieties are compared (as in the pepper example above), the differences between yields of two varieties must often be quite large before we can conclude that they are really different.
After the group of highest yielding, or in some cases, highest income2, varieties (see Figures 1 and 2 on page 24) has been identified, growers should select varieties within this group that have the best fruit quality (often the primary consideration), best disease resistance, or other desirable trait for the particular farm environment and market outlet being considered. One or more of these varieties can then be grown on a trial basis on your farm using your cultural practices.
Producers should also ask around to find out if other growers have had experience with the varieties in question. Growers who belong to a marketing cooperative should first ask the co-op manager about varieties, because in some cases buyers have specified the variety to be grown and packed by the co-op. Good marketing plans start with the customer's (market) requirements and work backwards to determine variety and production practices.
In cases where there are too many new varieties to test economically or when we suspect that some varieties will likely perform poorly in Kentucky, we may decide to grow each variety in only a single plot for observation. In this case we cannot make any statistical comparisons but can use the information obtained to eliminate the worst varieties from further testing. We can often save a lot of time and money in the process. We can also provide useful preliminary information to growers who want to try some of these varieties in their own fields.
Since there are so many new marketing opportunities these days for such a wide variety of specialty crops, we have decided that this single-plot approach for varieties unlikely to perform well in Kentucky is better than providing no information at all. We hope that RACE trials, described on page 9, will help fill a need and best use limited resources at the research farms. The hot and specialty pepper trial on pages 22-23 is the first example of such a trial.
In general, hybrid varieties (also referred to as F1) mature earlier and produce a more uniform crop. They often have improved horticultural qualities as well as tolerance and/or resistance to diseases. Hybrid seed is usually more expensive than is seed of open-pollinated (OP) varieties. With hybrid varieties, seeds cannot be collected and saved for planting next year's crop. Hybrid seed is now available for most vegetable crops that are grown in the United States.
Despite the advantages of hybrids, there are some crops for which few hybrids have been developed (poblano peppers, for example) or for which hybrids offer no particular advantages (most bean varieties). Interest in OP varieties has resurged in home gardeners and market gardeners who wish to save their own seed or who want to grow heirloom varieties for which only OP seed is available. Lower prices for produce in traditional wholesale market channels, however, may dictate that growers use hybrids to obtain the highest possible yields and product uniformity. Selecting a hybrid variety as a component in a package of improved cultural practices is often the first step toward improved crop quality and uniformity.
A seed source is listed for each variety reported in the trials. Seed source abbreviations with company names and addresses are found in Appendix A at the end of this publication. Because seeds are alive, their performance and germination rate depend on how old they are, where and how they were collected, and how they have been handled and stored. It is always preferable to purchase certified, disease-free seeds from a reputable seed dealer and to ask about treatments available for prevention of seed-borne diseases.
Many factors are considered when making a final choice of variety, including type, fruit quality, resistance or tolerance to pests, how early the variety is harvested, and cost. Keep in mind that some varieties may perform differently than in our trials, especially under different management systems. Producers should test varieties for themselves by trying two to three varieties on a small scale before making a large planting of a single variety. This method will be the best means of determining how well suited a particular variety is for your farm and market.
This publication is available online by following the links at: <http://www.ca.uky.edu/agc/pubs/pr/pr436/pr436.htm>. Other useful sources of information for commercial vegetable growers can be found at: <http://www.uky.edu/Agriculture/HLA/veglinks.htm> In addition, results of some pepper and blackberry trials will are posted on UK's New Crops Opportunities Center Web site under current research at: <http://www.uky.edu/Ag/NewCrops>.
Auburn University publishes a variety trial report twice a year in cooperation with several other universities. The Spring 2000 report is posted in pdf (Acrobat) format at: <http://www.ag.auburn.edu/resinfo/vegetables/spring2000.pdf>. Auburn has also provided a good comprehensive database of thousands of vegetable varieties that can be found at: <http://www.ag.auburn.edu/dept/hf/faculty/esimonne/vegetabl.htm>.
Rapid Action Cultivar Evaluation (RACE) trials are:
How do RACE trials differ from "observation trials"conducted in the past?
1 Portions of this article were adapted with permission from "Tips for Interpreting Vegetable Variety Trial Results" by Joe Kemble and Edgar Vinson in Spring 2000 Commercial Vegetable Variety Trials, Regional Bull. 5, Auburn University.
2It is often desirable to calculate a gross “income” variable for vegetable crop varieties that will receive different market prices based on pack-out of different fruit sizes and grades (bell peppers, tomatoes). In these cases yields in each size class/grade are multiplied by their respective wholesale market prices to determine gross returns (= income) for each cultivar in the trial.
Dave Spalding and Brent Rowell, Department of Horticulture
The Department of Horticulture has been conducting on-farm commercial vegetable demonstrations for more than a decade. As a result of drastic cuts (nearly 70%) in tobacco allotments over the last two years, numerous tobacco farmers made requests in 2000 for commercial vegetable demonstration plots. Given the small size and limited budget of the program, we could accommodate only a fraction of those requesting assistance.
On-farm demonstrations were conducted in Bath, Bourbon, Harrison, Lincoln, Marion, Washington, and Woodford counties. The grower/cooperators in both Bath and Harrison counties each grew 2 A of bell peppers and the cooperator in Bourbon county grew 5 A of bell peppers. In Lincoln county, the cooperator grew 1.5 A of staked tomatoes. Cooperators in Marion and Washington counties each grew 1 A of staked tomatoes. The cooperator in Woodford County grew ½ acre of mixed vegetables (staked tomatoes, bell peppers, green beans, sweet corn, cucumbers, summer squash, cantaloupes, watermelons, okra, and pumpkins) for local farmers' market sales. One-acre bell pepper plots were planted in Marion and Washington counties but were abandoned before any harvest was made. In addition to the grower/cooperators, the Extension associate with the UK Department of Horticulture also worked closely with other first-time commercial vegetable growers in Bath, Bourbon, and Marion counties. Data from these Bath and Bourbon county growers are also included in this report.
As in previous years, grower/cooperators were provided with transplants, black plastic mulch, and drip irrigation lines for up to 1 A and were allowed to use the Department of Horticulture's equipment for raised bed preparation and transplanting. The cooperators supplied all other inputs, including labor and management of crops. In addition to identifying and working closely with cooperators, county Extension agents took soil samples from each plot and scheduled, promoted, and coordinated field days at each site. The Extension associate made regular weekly visits to each plot to scout crops and make appropriate recommendations.
The bell pepper demonstration plots were transplanted using three different bacterial spot-resistant varieties (`Enterprise,' `Lexington,' and `X3R Ironsides'). Peppers were transplanted into 6-inch high raised beds covered with black plastic with drip lines under the plastic. Plants were transplanted 12 inches apart in an offset manner in double rows that were 15 inches apart. Raised beds were 6 ft from center to center. The staked tomato demonstration plots were transplanted with the variety `Mountain Fresh.' Tomatoes were transplanted into 6-inch-high raised beds covered with black plastic with drip lines under the plastic. Plants were transplanted 18 inches apart in single rows with the raised beds spaced 6 ft apart from center to center. Tomatoes were pruned, staked, and tied using the Florida Weave System. The plots were sprayed with the appropriate fungicides and insecticides on an as-needed basis, and the cooperators were asked to follow the fertigation schedules provided in the 2000-01 Vegetable Production Guide for Commercial Growers (ID-36). The independent growers in Bath and Bourbon counties provided all their own inputs and equipment. The Extension associate made regular visits to those farms to scout the crops and make recommendations. Production practices on these farms were essentially the same as those for the demonstration plots.
The summer of 2000 was a much better growing season than the drought year of 1999. Most of the plots were transplanted in a timely manner, and growing conditions were good. Two of the original bell pepper demonstration plots were transplanted later than the optimum planting period and suffered as a result. Both of these plots were abandoned prior to harvest, and no data could be collected.
Although 2000 wholesale bell pepper prices were moderate, yields were high, resulting in high net returns ranging from $2,000/A to an incredible $5,000/A for the grower/cooperators (Table 1). The Bath county pepper demonstration plot was nearly destroyed by a severe hailstorm after the first harvest. The cooperator fortunately had crop insurance, and this is reflected in returns in Table 1. The independent pepper growers advised by the program achieved $3,309/A and $4,825/A net returns (Table 3). Figures in Tables 1 and 3 include sales of both fresh market green peppers sold through the Central Kentucky Grower's Cooperative in Georgetown and red mature fruits sold to a processor at the end of the harvest season.
Overall, weeds seemed to be the biggest problem for all the growers. Bacterial spot occurred in some pepper fields but never became a serious problem. Bacterial spot, or speck, was common and affected marketable yields in some tomato fields. Relatively low wholesale prices hurt the staked tomato producers the most (Table 2). These plots were located in central Kentucky where harvests were 10 to 14 days later than those of south-central and western Kentucky, where considerably better returns were achieved. The usual midseason glut occurred so that prices had declined by the time production peaked in the central Kentucky demo plots. Returns ranged from a loss of $690/A to a profit of $2,657/A.
The one grower/cooperator in Woodford County who chose to grow a variety of vegetable crops on a half-acre for direct market sales did extremely well, reporting the highest net return of $7,368/A.
Most of the grower/cooperators used migrant labor in their operations and seemed well pleased with the way in which vegetable production complemented their tobacco production. Most of the cooperators and independent growers assisted by this program, all of whom were growing vegetables commercially for the first time, achieved high yields and in the case of bell peppers, exceptional returns. Most of them indicated that they intended to continue vegetable production, with several planning to expand in 2001.
| Table 1. Bell pepper costs and returns of grower/cooperators. | |||
| Inputs |
(2 A) |
(5 A) |
(2 A) |
| Plants |
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| Fertilizer |
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| Black Plastic |
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| Drip Lines |
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| Fertilizer Injector |
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| Herbicide |
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| Insecticide |
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| Fungicide |
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| Water |
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| Labor |
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| Machine Costs |
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| Co-op Marketing Fees |
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| Total Expenses |
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| Yield |
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| Income |
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| Net Income |
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| Net Income/A |
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| Dollar Return/ Dollar Input |
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* Cost amortized over three years.
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| Table 2. Staked tomato costs and returns of grower/cooperators. | |||
| Inputs |
(1 A) |
(1.5 A) |
(1 A) |
| Plants |
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| Fertilizer |
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| Black Plastic |
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| Drip Lines |
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| Fertilizer Injector |
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| Stakes |
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| Herbicide |
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| Insecticide |
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| Fungicide |
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| Water |
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| Labor |
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| Machine |
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| Total Expenses |
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| Yield |
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| Income |
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| Net Income (loss) |
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| Net Income (loss)/A |
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| Dollar Return/ Dollar Input |
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| * Cost amortized over three years. ** Includes the cost of fuel and five-year amortized cost of irrigation equipment. |
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| Table 3. Bell pepper (independent growers, Bath and Bourbon counties) and mixed vegetable (grower-cooperator, Woodford County) costs and returns. | |||
| Inputs |
(2 A) |
(5 A) |
(0.5 A) |
| Plants |
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| Fertilizer |
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| Black Plastic |
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| Drip Lines |
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| Fertilizer Injector |
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| Herbicide |
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| Insecticide |
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| Fungicide |
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| Water |
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| Labor |
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| Machine costs |
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| Total Expenses |
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| Yield |
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| Income |
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| Net Income |
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| Net Income/A |
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| Dollar Return/ Dollar Input |
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* Cost amortized over three years. |
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Gerald R. Brown and Dwight Wolfe, Department of Horticulture
Although apples are the principal tree fruit grown in Kentucky, the hot, humid summers and heavy clay soils make apple production more difficult for growers in this state than those in the major apple producing regions where soil and climate are more favorable. Kentucky still imports more apples than it produces. Peach production can be expected to be erratic because of our extreme temperature fluctuations occurring in the winter and spring.
In spite of these challenges, productive orchards are one of the highest income enterprises suitable for upland rolling soil; they also have a low potential for soil erosion. Also, the strong market for peaches continues to encourage growers to plant peach trees.
Continued identification of improved rootstocks and cultivars is required for growth of the Kentucky fruit industry. For these reasons, Kentucky continues to be a cooperator along with 39 other states and three provinces in Canada in the Cooperative Regional NC-140 Project: Rootstocks and Interstem Effects on Pome and Stone Fruit.
The NC-140 plantings are of utmost importance to Kentucky for gaining access to and testing new rootstocks from around the world. The detailed and objective evaluation of these rootstocks will provide growers with the information needed to select the most appropriate rootstocks for their needs in the future when they become commercially available.
The 1994 and 1999 Apple Rootstock Planting will provide us with needed information on adaptability of the slender spindle and the vertical axe systems to trees grown on our fertile soils. The 1994 Peach Planting should provide us with needed information to determine if tree survival, winter hardiness, and cropping frequency can be improved by using any of the recently developed rootstocks.
The NC-140 orchard systems plantings are regularly used as demonstration plots for visiting fruit growers, Extension personnel, and research scientists. The research data collected in these trials will help to establish base-line production and economic records for the various orchard system/rootstock combinations that can be used later by orchardists in Kentucky.
Scions of known cultivars on various rootstocks were produced by commercial nurseries and distributed to cooperators for each planting. The University of Kentucky has three NC-140 rootstock plantings at the UK Research and Education Center at Princeton:
Trees of each rootstock were allocated to blocks (rows) in a randomized block design (that is, each rootstock appears once and at random within each block [row]). Soil management is a 6.5 ft herbicide strip with mowed-sod alley ways. Trees are fertilized and sprayed according to UK recommendations (1, 2). Yield, trunk circumference, and maturity indices such as soluble solids are measured annually for each planting.
The winter of 1999-2000 in Kentucky was mild, followed by a late freeze and adequate rainfall throughout the growing season. Fruit generally had excellent quality in terms of color, size, and flavor.
1994 Apple Semidwarf Rootstock Planting. The 1994 semidwarf apple rootstock planting is the first trial at this station to be trained to the French vertical axe system. It also includes a number of new stocks along with some that have performed well in previous plantings at the UK Research and Education Center, Princeton.
This planting was established as planned, except for the substitution of B.9 for P.1. Trickle irrigation was installed, and a trellis system was constructed in 1995. The mortality of trees on M.26 (10% survival) differed significantly from trees on the other three rootstocks (100% survival for trees on CG.11 and 90% for the others). The percent soluble solids, the weight of picked and dropped fruit, cumulative yield, 2000 yield, trunk circumference, and the number of root suckers varied significantly by rootstock (Table 1). Flesh firmness did not vary significantly by rootstock.
| Table 1. 2000 Results NC-140 1994 Apple Semidwarf Rootstock Planting.1 | |||||||||
| Rootstock2 |
|
Picks |
Drops |
Yield3 (lb/tree) |
Fruit |
|
Soluble Solids |
Circumference (in) |
Root Suckers |
| CG.30 |
|
|
|
|
|
|
|
|
|
| V.2 |
|
|
|
|
|
|
|
|
|
| M.26 EMLA |
|
|
|
|
|
|
|
|
|
| B.9 |
|
|
|
|
|
|
|
|
|
| Average |
|
|
|
|
|
|
|
|
|
| LSD (.05) |
|
|
|
|
|
|
|
|
|
| 1 University of Kentucky Research
and Education Center, Princeton. 2 Arranged by cumulative yield in descending order. Note: Trunk circumference and yield are usually directly correlated. |
|||||||||
1999 Dwarf and Semidwarf Apple Rootstock Plantings. This planting consists of two groups of apple rootstocks, a dwarfing group with 11 rootstocks, and a semidwarfing group with six rootstocks. Eight of the dwarfing rootstocks and three of the semidwarfing ones have not been tested at the Princeton station.
Ninety trees out of a possible 108 are included in our planting because 12 were not available for our site (one CG.16N, two CG.13, three CG.41, one CG.814, and four CG.30N). Furthermore, three trees never leafed out after planting (one CG.16T, one CG.16N, and one CG.41N). In spite of the 1999 drought, all the others appear to be alive.
Significant differences were observed for the number of flower clusters/tree and for trunk circumference for both groups of rootstocks (Table 2). Significant differences were observed for growth in trunk circumference for the semidwarfing rootstocks but not for the dwarfing ones. Conversely, the number of root suckers did not vary significantly for either the dwarfing rootstocks or the semidwarfing ones.
| Table 2. 2000 results NC-140 1999 Apple Dwarf and Semidwarf Rootstock Planting.1 | ||||||
|
Rootstock Dwarfing2 |
Trunk |
Trunk |
No. |
No.Trees Planted |
No. Trees Lost3 |
|
| Mar 00 | Oct 00 | |||||
| CG.13 | 3.0 | 5.2 | 2.3 | 155 | 4 | 0 |
| G.16N | 2.0 | 4.9 | 2.9 | 57 | 5 | 1 |
| G.16T | 2.0 | 4.7 | 2.6 | 108 | 6 | 1 |
| CG.41 | 2.0 | 4.1 | 2.0 | 42 | 3 | 1 |
| Sup.1 | 2.0 | 4.0 | 2.0 | 79 | 6 | 0 |
| Sup.3 | 2.0 | 4.0 | 2.0 | 71 | 6 | 0 |
| CG.179 | 1.9 | 4.2 | 2.3 | 59 | 6 | 0 |
| Sup.2 | 1.9 | 4.2 | 2.3 | 56 | 6 | 0 |
| CG.202 | 1.9 | 4.1 | 2.3 | 7 | 5 | 0 |
| M.9 | 1.6 | 3.2 | 1.6 | 33 | 6 | 0 |
| M.26 | 1.5 | 3.3 | 1.8 | 12 | 6 | 0 |
| Average | 1.9 | 4.2 | 2.2 | 60 | -- | -- |
| LSD (0.05) | 1.6 | 0.9 | 0.9 | 61 | -- | -- |
| Semidwarfing2 | ||||||
| CG.30N | 2.4 | 5.0 | 2.6 | 85 | 2 | 0 |
| Sup.4 | 2.4 | 3.8 | 1.4 | 31 | 6 | 0 |
| M.7 | 1.9 | 4.2 | 2.3 | 39 | 6 | 0 |
| CG.707 | 1.7 | 4.1 | 2.5 | 8 | 6 | 0 |
| CG.814 | 1.6 | 3.8 | 2.3 | 12 | 5 | 0 |
| M.26 | 1.5 | 3.6 | 2.1 | 17 | 6 | 0 |
| Average | 1.9 | 4.0 | 2.1 | 26 | -- | -- |
| LSD (0.05) | 2.4 | 0.7 | 0.7 | 29 | -- | -- |
| 1 University of Kentucky Research and Education
Center, Princeton. 2 Ranked by size of trunk circumference at planting, indescending order. 3 These trees never leafed out after planting (first week in March 1999). |
||||||
1994 Peach Rootstock Planting. Peaches are one of the most popular fruits in Kentucky. The strong market for this crop continues to entice growers to plant trees in spite of the fact that one can expect erratic production due to the extreme temperature fluctuations that occur in the winter and spring in this state.
A rootstock that is more suitable to the Kentucky's climate than ones traditionally used would be of great value to the fruit industry in the state. A rootstock that could significantly delay bloom would change the future of the Kentucky peach industry. To date, 75 of the 94 trees planted in this trial are alive (80% survival). Statistical differences were observed for trunk circumference, 2000 yield, and date of 90% bloom (Table 3), but not for cumulative yield, average fruit weight, number of root suckers, and soluble solids. The Julian date for 10% maturity was 189 for all trees, except for those on Ishtara and Ta Tao, which was 193.
| Table 3. 2000 Results 1994 NC-140 Peach Rootstock Planting.1 | |||||
| Rootstock2 |
Yield/Live Tree (lb) |
(lb/tree) |
Circumference (in) Spring |
Fruit Wt (oz fruit) |
Julian Bloom Date |
| Lovell |
|
|
|
|
|
| BY 520-8 |
|
|
|
|
|
| CF 305 |
|
|
|
|
|
| Montclar |
|
|
|
|
|
| BY 520-9 |
|
|
|
|
|
| Rubira |
|
|
|
|
|
| Stark's Redleaf |
|
|
|
|
|
| Ta Tao 5 |
|
|
|
|
|
| Tenn Natural |
|
|
|
|
|
| Bailey |
|
|
|
|
|
| Ishtara |
|
|
|
|
|
| Higama |
|
|
|
|
|
| Average |
|
|
|
|
|
| LSD (.05) |
|
|
|
|
|
| 1 University of Kentucky Research and Education
Center, Princeton. 2 Ranked in descending order of cumulative yield. |
|||||
1. Brown, Gerald R. and Dwight Wolfe. 2000. Rootstock and Interstem Effects on Pome and Stone Fruit Trees. Fruit and Vegetable Crop Research Report: 1998. University of Kentucky (publication PR-410:8-11).
2. Brown, Gerald R. and Dwight Wolfe. 2000. Optimal Training of Apple Trees for High-Density Plantings. Fruit and Vegetable Crop Research Report: 1998. University of Kentucky (publication PR-410:12-13).
Gerald R. Brown and Dwight Wolfe, Department of Horticulture
Early production and optimal fruit size on vigorous sites are obtained when photosynthates are balanced properly between flower bud initiation and vegetative growth. Kentucky growers often have a problem with excessive vegetative growth or vigor, which greatly reduces the production that can be achieved from high density apple plantings. Pruning and training are possibly the most important techniques used by fruit growers to maintain the proper balance between flower bud initiation and vegetative growth. Identification of effective pruning and training techniques for vigorous sites is required for continued expansion of apple production in Kentucky. The University of Kentucky College of Agriculture and the Kentucky State Horticultural Society have made a long-term commitment to help meet this need for effective pruning and training techniques. For this reason, research was initiated to determine the training and pruning practices needed to obtain early production and optimal fruit size from trees trained to either the slender spindle or French axe system on vigorous sites.
One hundred-eighty trees of Golden Delicious on M.9 rootstock were set out in May 1997 at Princeton in a randomized complete block design with eight treatment combinations (five rows, 32 trees/row). Trunk circumference averaged 2 ft at planting and did not vary significantly among rootstocks. A trellis was constructed, and trickle irrigation was installed. Tree spacing is 8 ft apart within rows with the rows 16.4 ft apart. Soil management is a 6.5 ft herbicide strip with mowed sod alley ways. Trees are fertilized and sprayed according to Kentucky recommendations (1,2). Yield (beginning with 1998), trunk circumference, and maturity indices such as soluble solids and flesh pressure are measured annually.
The trees were trained according to a prescribed treatment protocol (Table 1). Trees began to fill their allotted space in 1999, and leader management was modified to maintain leaders at specified heights (Table 1). Limbs of one tree overlapping or touching those of adjacent trees were headed back into two-year-old wood.
| Table 1. Summer pruning/training treatments of the UK-KSHS 1997 apple training study at Princeton, KY. | ||||||
| System |
Pruning Level | Amount of 1-Year-Old Wood Left after Heading at Planting |
Angle1 | Limbs2 | Leader Management | |
| 19993 | 20004 | |||||
| French Axe | Light | Not headed | 45º | No | D | 12 |
| French Axe | Moderate | 12-16 in | 45-60º | Yes | C&D | 11 |
| French Axe | Moderate | 12-16 in | 45-60º | Yes | D | 11 |
| French Axe | Heavy | 8-12 in | 60-90º | Yes | D | 10 |
| Slender Spindle | Light | Not headed | 45º | No | A | 9 |
| Slender Spindle | Moderate | 14-20 in | 45-60º | Yes | B | 9 Y |
| Slender Spindle | Moderate | 14-20 in | 45-60º | Yes | B | 9 Y |
| Slender Spindle | Heavy | 10-14 in | 60-80º | Yes | C | 9 Z |
| 1 Angle to which limbs are to be positioned. 2 For French Axe, yes = completely remove overly vigorous branches with narrow angles when 3 to 6 inches long. For Slender Spindle, yes = completely remove branches that compete with leader, no = limbs not pruned. In 2000, for both training systems, limbs overlapping or touching those of adjacent trees were headed back into 2-year-old wood. 3 A = weak leader renewal and new leader headed at 12 inches. B = bend leader at 60 angle, alternating direction with every 18 inches of new growth. C = leader bagged 1 month prior to bud break and bag removed at appropriate time. D = leader bent to horizontal, alternating direction after buds break on top side. 4 Leaders were maintained at specified heights (in ft) by cutting to an alternate leader when necessary. Y = Alternate leader was bent to horizontal for 6 weeks. Z = alternate leader was "snaked" throughout growing season. |
||||||
Cumulative yield and yield for the year 2000 was significantly less for the light pruning level compared to the other three levels of pruning (Table 2). No differences among the four pruning levels were observed in fruit size (average fruit weight), trunk circumference, number of root suckers, flesh firmness, and soluble solids. Differences between the French axe and slender spindle systems were not observed for any of the above variables. Less than 25% of the time that was spent in previous years was required to train the trees in the year 2000.
This and other plantings are regularly used as demonstration sites for visiting apple growers, Extension personnel, and researchers. The data collected in these trials will help to establish baseline production methods and provide an economic basis for the various orchard system/rootstock combinations, which can be later utilized by orchardists in Kentucky.
| Table 2. Time requirements and effects of summer apple pruning/training treatments on apple yields at Princeton KY, 2000. | ||||||||||
|
Pruning Level-- |
Trunk Circumference (in) |
Yield2 /Tree (lb) | Avg Fruit Wt (oz) |
Time Required for |
Total Minutes/ Tree |
Pruning/ Training (minutes/lb fruit) |
||||
| Cumulative | 2000 | |||||||||
| 1997 | 1998 | 1999 | 2000 | |||||||
| Light - 1 | 6.9 | 30.4 | 11.2 | 8.9 | 12.2 | 10.2 | 18.2 | 4.4 | 45.0 | 1.5 |
| Moderate - 2 | 6.6 | 47.5 | 23.4 | 8.7 | 09.6 | 08.6 | 16.5 | 3.4 | 38.1 | 0.8 |
| Moderate - 1 | 6.7 | 43.4 | 23.7 | 8.4 | 11.4 | 11.1 | 19.1 | 2.1 | 43.7 | 1.0 |
| Heavy - 1 | 6.6 | 42.3 | 21.4 | 8.3 | 11.9 | 12.0 | 21.6 | 2.5 | 48.0 | 1.1 |
| Average | 6.7 | 41.4 | 19.9 | 8.7 | 11.3 | 10.3 | 18.9 | 3.0 | 43.5 | 1.0 |
| LSD (P=0.05) | 0.5 | 7.50 | 6.60 | 0.7 | NA | NA | NA | NA | NA | NA |
| 1 The protocol was changed in year 2000 from 1)
pruning every week and 2) pruning every other week to pruning once early
in the season on all treatments. 2 Yield is the sum of picked and dropped fruit. Dropped fruit averaged less than 3 lb/tree. 3 Total summer pruning and training periods were 14 weeks (1997), 12 weeks (1998), 16 weeks (1999), and four weeks (2000). |
||||||||||
1. G.R. Brown, R.T. Jones, J.G. Strang, L.A. Lester, J.R. Hartman, D.E. Hershman, R.T. Bessin: 1998. Commercial Tree Fruit Spray Guide. University of Kentucky, College of Agriculture Cooperative Extension Service (publication ID-98).
2. Midwest Tree Fruit Handbook, University of Kentucky, College of Agriculture Cooperative Extension Service (publication ID-93).
Ric Bessin and Kerry Kirk, Department of Entomology; John Hartman, Department of Plant Pathology; Joe O'Leary, Department of Animal Sciences; and Jerry Brown and John Strang, Department of Horticulture
A survey was sent to apple growers and cider producers in Kentucky to determine common practices, with a focus on food safety in several areas of production including:
Survey results will be used to design educational materials for both producers and consumers in an ongoing effort to ensure the high quality and safety of apple products and the continued productivity of Kentucky apple growers.
The survey contained 70 questions, which included 62 graded multiple choice questions and eight open response questions. The questions were grouped to cover the following topics.
Addresses of potential growers were obtained using current subscription information from a grower mailing list, grower directories, and phone records. It should be noted that not all addresses were strictly those of apple producers, as the mailing list and grower directories were for producers of all fruit types in Kentucky. A total of 110 surveys were sent out. Responses to the first mailing were few, so another mailing to the addresses that did not respond to the first attempt was made within 60 days. Phone numbers were available for some addresses, and surveys were filled out by telephone for respondents at some of these addresses. A total of 31 surveys were completed. It can be expected that many of the surveys were not completed or returned due to bad addresses, nonapplicability, or lack of interest.
Growers reported a total of 439 A of apples, with the largest farm at 118 A and the smallest at 0.06 A. The survey sample represents about 44% of the total apple acreage in the state (total Kentucky apple acreage is estimated at about 1,005 A). The average farm size reported was 14.7 A. Cider production amounts were reported from 13 growers in the open response questions, but 18 growers answered cider production questions. From those listing a production amount, 31,650 gal of apple cider was produced, with the average farm producing 2,434 gal. Only about one-third of the growers reported that they had purchased apples for cider production in the past. About 27% reported producing cider for other growers.
Most growers surveyed were implementing IPM principles, understood the importance of disease forecasting, water quality, worker cleanliness, proper use and rates of pesticides and pesticide application equipment, and orchard cleanup. The survey showed, however, that more could be done in soil, foliar, and water (pH) testing, pheromone trapping, and degree-day monitoring of pests to improve pesticide application timing. Over half the growers surveyed reported at least some confusion about using pesticides so that the chance of pesticide resistance development would be reduced.
Protecting fruit from microbial contamination was a major part of the survey. Growers appear to have a solid understanding of how to prevent microbial contamination of fruits. They reported knowledge of the importance of cleaning storage and processing equipment, not using damaged or dropped fruit for cider production, and chilling cider after production.
Practices that need to used more widely by growers include:
Pasteurization is expected to increase rapidly due to the Kentucky Department of Agriculture helping apple growers purchase equipment through cost sharing.
The following cider production data were reported:
When asked about key insect, disease, and production problems, answers varied. The top three answers for each of these categories in descending order, were:
The number of pesticide applications/crop varied greatly. Fungicide/bactericide applications varied the most, with a high of 20 applications and a low of one application. The average was nine. This trend also was shown in insecticide and to a lesser extent, herbicide application numbers. Insecticide applications averaged eight/crop, with a high of 16 applications and a low of two. There were fewer herbicide applications overall, with an average of two applications/crop, a high of 11, and a low of none.
The information gleaned from this survey is being used to help design educational programs and materials for Kentucky apple growers, cider producers, and consumers. Based on the survey, certain areas need attention, including:
It is possible that education and implementation of at least some these procedures will reduce the number of sprays by growers who responded in the survey that they had made the most pesticide applications.
R. Terry Jones, William Turner, and John C. Snyder, Department of Horticulture
David C. Ditsch, Department of Agronomy
Blueberries are native to Kentucky. While limited commercial acreage has been established in Kentucky, blueberries have an excellent potential for local sales and U-pick operations. Recent research into the health benefits of small fruits like blueberries may help further boost sales.
Two blueberry plantings were established in the fall (October) of 1996 at the University of Kentucky Robinson Station at Quicksand and the Laurel Fork Demonstration Site in the southeastern corner of Breathitt County. Growth, yield, and survival of various blueberry cultivars were compared between a normal silt loam site (Robinson Station) and a disturbed mine site (Laurel Fork). The plantings consisted of eight to 12 rows of various cultivars in a randomized complete block design. Plants were 4 ft apart in raised beds 14 ft apart. Drip irrigation with point source emitters (2 gph/plant) was installed shortly after planting. Plants were fertilized beginning in the spring of 1997. One application of 5 lb/100 ft of 5-20-20 followed by a side-dressing of 2 lb ammonia sulfate/100 ft of row at bloom was applied each year. Netting was used at both sites to prevent loss due to birds. The Laurel Fork site is also at a higher elevation, and apple tree bloom stages at this site are seven to 10 days later than similar cultivars at Quicksand.
Sixteen cultivars at Quicksand and 13 cultivars at Laurel Fork were tested, and results are shown in Tables 2 and 3, respectively. At Quicksand, Briggitta, Reka, Bluejay, and Bluegold were the highest yielding cultivars. Bluejay and Bluegold were not significantly different from Bluecrop, Duke, or Sierra. Toro had the largest berry size, which was not significantly different from Blueray, Ozarkblue, Briggita, Spartan, Patriot, or Bluecrop. Duke was the earliest maturing blueberry, with 70% of its fruit picked during the first two harvests.
At Laurel Fork, Reka was the highest yielding blueberry. Reka had 54% more fruit than the second highest yielding blueberry cultivar at this site (Bluegold). Bluegold, Patriot, Duke, Nelson, Bluecrop, Bluejay, and Sierra all had yields that were not significantly different from each other. Nelson had the largest berries at Laurel Fork, followed by Duke, Blueray, Toro, Briggitta, Bluecrop, Patriot, Sierra, and Bluegold. These were not significantly different from Nelson or each other. Duke was again the earliest maturing blueberry cultivar, with 81% of its fruit harvested during the first two pickings. In trials at Princeton, Duke was also the earliest maturing cultivar tested.
In general, the blueberry yields were higher on the undisturbed soil site at Quicksand, and the plants at Quicksand were slightly larger than those on the mine spoils. Reka seemed to have high yields and vigorous growth (growth data not shown) at both sites. For some reason Briggitta, the highest yielding cultivar at Quicksand, did not do as well at Laurel Fork. These data represent only the first harvest response of the various cultivars after three-and-a-half years of growth. Additional harvests and observations will be needed to determine which cultivars are the best performing over time in Kentucky.
For additional blueberry information and trial results, see also:
— Strang, John, R. Terry Jones and G. R. Brown. 1989. Growing Highbush Blueberries in Kentucky. University of Kentucky College of Agriculture Cooperative Extension Service (publication HO-60).
— Wolfe, Dwight and Gerald Brown. 1998. Blueberry Cultivar Trial. Fruit and Vegetable Crop Research Report: 1998. (publication PR-410: 17).
— Wolfe, Dwight and Gerald Brown. 1999. Blueberry Cultivar Trial. 1999 Fruit and Vegetable Crops Research Report. (publication PR-410:17).
|
Table 1. 1996 Laurel Fork and Quicksand Blueberry Soil
Test Results.
|
|||||||
| Location | pH | Buf-pH | P | K | Ca | Mg | Zn |
| ------------------------ lb/A ------------------------ | |||||||
| Laurel Fork Mine Site1 | 5.9 | 7.2 | 46 | 206 | 1057 | 541 | 10.7 |
| Quicksand | 5.7 | 6.5 | 14 | 173 | 1497 | 126 | 5.1 |
|
1 Mine soil pH adjusted with granular sulfur
at 2.5 lb/100 sq ft in late summer 1996 two months prior to planting.
Both sites received 2.5 cubic ft of Canadian peat/50 sq ft of bed area
prior to raised bed formation. Additional peat of 0.13 cubic ft was placed
in each planting hole at the time of planting. Granular elemental sulfur
0.75 lb/100 sq ft was applied to the beds at Quicksand.
|
|||||||
|
Table 2. Yield and quality of blueberry cultivars at
Quicksand, KY, 2000.
|
||||||
|
Cultivar1
|
( oz)/Bush2 |
(oz)/Berry2 |
Visual Size Rating3 |
Taste4 | Appearance5 | % Total Fruit First Two Harvests6 |
|
Briggitta
|
|
|
L | T | A | 0 |
|
Reka
|
|
|
SM | ST | A | 15 |
|
Bluejay
|
|
|
ML | ST | A+ | 13 |
|
Bluegold
|
|
|
L | SB | A | 1 |
|
Bluecrop
|
|
|
VL | ST | A | 14 |
|
Duke
|
|
|
L | S | A+ | 70 |
|
Sierra
|
|
|
ML | ST | A | 13 |
|
Ornablue
|
|
|
S | B | A- | 0 |
|
Toro
|
|
|
VL | ST | A+ | 23 |
|
Ozarkblue
|
|
|
L | ST | A | 13 |
|
Blueray
|
|
|
VL | B | A | 10 |
|
O'Neal
|
|
|
L | S | A+ | 56 |
|
Nelson
|
|
|
L | ST | A | 1 |
|
Patriot
|
|
|
L | T | A | 33 |
|
Jersey
|
|
|
ML | ST | A | 1 |
|
Spartan
|
|
|
L | S | A | 49 |
|
LSD (P=0.05)
|
|
|
||||
|
1 In descending order of yield. | ||||||