Vol. 3, No. 2 September 1999
Preplant Decisions Greatly Impact Future Disease Risk
Making No-Till Wheat Production Profitable
Planting Farmer Saved Wheat Seed - Are You Really Saving Money?
Economic Summary of On-Farm Tillage Comparisons
Many Kentucky wheat producers have their
total disease management program in place once the seed is in the ground.
By that time, numerous decisions have been made, either specifically or
by default, including: crop rotation, tillage/seedbed preparation, variety
and seed quality, seed treatment, planting date, method, and seeding rate;
and fall fertility. Individually and collectively, these factors can play
a very important role in future disease development and, thus, yield loss
due to diseases.
Crop Rotation and Tillage: These
production variables are linked when it comes to disease management in
wheat. For example, in a field where wheat is sown following corn or soybean,
tillage is inconsequential for most wheat pathogens. That is, levels of
most pathogens will be similar whether wheat is planted no-till or following
conventional tillage. Fortunately, most wheat fields grown for grain in
Kentucky are planted behind either corn or soybean. In contrast, when wheat
is planted in consecutive years in a field, pathogens that either survive
in crop residue or require more than a few months for populations to decline
may be more severe the second time wheat is grown in a field. This is especially
true where a field is planted no-till because of the high levels of wheat
residue that will exist in that production system. Examples of common diseases
where the causal organism survives in wheat straw are: take-all, speckled
leaf blotch, leaf and glume blotch, and tan spot.
In rare instances, no-tillage may enhance
seed and seedling disease problems simply due to the effect of surface
residue on soil temperature and moisture. Overall, soil moisture levels
will be increased when the soil surface is covered with a high percentage
of residue of any previous crop or even weeds. In addition, surface residue
tends to keep soil temperatures warmer in the fall and cooler in the spring
compared to fields with low levels of surface residue (i.e., tilled fields).
Examples of diseases that may be slightly worse in no-till include: seed
and seedling diseases caused by Pythium or Fusarium, take-all disease,
and soil-borne viruses. Many producers fear that substantially more Fusarium
head blight (FHB) will develop when wheat is planted no-till behind corn.
Although the risk for slightly more FHB does exist with this system,
there is no evidence that FHB will be noticeably more severe than in a
conventionally-tilled field, regardless of previous crop. Weather conditions
just before, during, and for two weeks after flowering appear to play the
dominant roles in determining the incidence and severity of FHB in a field
Variety Selection: The disease resistance
characteristics of the wheat variety (ies) you plant will have a tremendous
impact on the potential for certain important fungal and viral diseases
to develop later. However, no one variety is resistant to all diseases
for which resistance is available. Thus, it is important to plant more
than one variety with different resistance characteristics to reduce the
risk that any one disease will cause serious losses. There are some diseases,
such as take-all, for which no resistance is available. In those instances,
which variety you plant will not affect disease development. There are
some disease situations where the potential for disease in an otherwise
susceptible variety is impacted by some growth characteristic of that particular
variety. For example, because FHB is weather dependent during crop flowering,
planting a few varieties that may flower during slightly different periods
may limit the extent of FHB on a farm due to escape.
Seed Quality and Seed Fungicides:
In all situations we recommend you plant only high quality seed if grain
production is your goal. The use of a broad-spectrum seed treatment fungicide
with this seed may protect stands from seed and seedling should soil conditions
become stressful due to adverse weather or planting method; however, seed
treatment should be looked at in a risk management context. That is, do
not expect seed treatment fungicides to enhance stands and yields in most
situations. But, depending on the risk level that one is willing to assume,
some producers might be willing to spend the additional $1.25 - 1.50 per
bushel of seed to reduce the risk that disease might affect stand establishment.
If loose smut is a concern in any seed
lot, we recommend you treat the seed with a smut-effective fungicide such
as Raxil or Dividend. A small amount of loose smut in a seed production
field can result in a serious epidemic and yield losses when that seed
is planted the following year. This concern is especially valid where saved
seed is planted!
Planting Date: By avoiding early
planting dates, you could significantly reduce the potential for certain
diseases to develop. For example, if you delay planting wheat until after
the Hessian fly-free date for your area, the risk that a serious barley
yellow dwarf (BYD) problem will develop is greatly diminished. Similarly,
avoiding early planting dates may limit the severity of take-all disease
and the soil-borne viruses, such as wheat spindle streak mosaic.
Nitrogen Fertility and Seeding Rate:
Excessive top growth in the fall, which is encouraged by high nitrogen
fertility and/or excessive seeding rates, may enhance certain diseases
and should be avoided. Leaf rust, for example, may develop to a significant
extent in the fall and this can increase the risk that the disease will
successfully overwinter and cause serious losses the following spring.
Excessive top growth in the fall also encourages aphid development and
survival and this, in turn, can result in greater levels of BYD.
Four field tests of no-till wheat have
been established on Kentucky farms. Those tests are in Caldwell, Daviess,
Fayette, and Logan Counties. The UK Wheat Science group is managing the
Caldwell and Fayette tests, Opticrop is managing the Daviess test, and
WheatTech is managing the Logan test. Each test includes two replications
with 4 strips per replication. Two of those four strips are no-till; the
other two strips are managed with conventional tillage. Each group has
chosen two different wheat varieties to plant in their tests. Management
practices have been implemented to attempt to maximize profitability of
both conventional and no-tillage systems.
Preliminary results below show that, on avg, no-till stand establishment was similar to conventional stand establishment. However, no-till stands were lower than conventional stands for both the Daviess and Logan tests, but higher for both the Caldwell and Fayette tests. This difference should be taken into account when interpreting yield data we collect later this summer. Corn residue levels were very low for conventional tillage, and very high for no-tillage. This should make for a sharper contrast than we had in the previous year's tests, in which residue levels for conventional tillage ranged from 33 to 66%.
(Plants/yd2) Cover (%)
Winter and spring weather has been relatively
kind to our wheat trials this season. However, there was some delay in
applying spring N, especially on the Caldwell test. This would be expected
to be to the disadvantage of that trial in general, and of the no-till
plots in particular. So far, weed control, insect control, and disease
management has been effective at all four sites. We will continue to monitor
these studies, and will be reporting yields soon after harvest.
Wheat grain yields in 1999 were excellent
in most regions of the state, however grain prices are low and many farmers
are trying to cut corners to save on production costs for next year. One
area considered is planting farmer saved seed. Thus, farmers must decide
if they should purchase planting seed of private or public varieties OR
plant bin-run seed from their own production or that of a neighbor. There
are advantages and disadvantages that must be considered before this decision
Variety Selection and Cost of Seed:
Most farmers are well aware of the wide
range of excellent public and private varieties available and can compare
performance of these varieties in data from performance trials conducted
by the University of Kentucky or other sources. If seed is purchased from
a dealer the cost may range from $7.00 to $16.00 per 50 lb. unit for privately
developed varieties to $5.00 to 7.00 per 50 lb. unit for certified seed
of publicly developed varieties. Thus, at a seeding rate of 35 seeds per
sq. ft. the seed cost may range from $15.00 to 45.00 per acre (depending
on the variety purchased and its seed size).
If seed is planted from the farmers bin
the costs will vary depending on the following: was the seed cleaned, bagged,
treated and tested prior to planting? Custom cleaning costs in Kentucky
range from $1.25 to 2.00 per bushel depending on additional fees for bagging
and storage. If the seed is treated with a fungicide it may cost another
$1.25 to 1.50 per bushel. Thus, assuming $2.50 per bushel for market wheat
the cost of farmer saved wheat may range from $9.50 to 15.00 per acre.
This appears to be an advantage for farmer save seed especially over private
varieties, BUT other factors must be considered.
All certified seed and seed of most privately developed varieties has passed both field inspection and seed testing standards for varietal purity, freedom from certain weed and other crop seeds and certain diseases (i.e. loose smut). In addition, most certified seed and seed of private varieties has been treated with a fungicide to control seed-borne (i.e. loose smut) and seedling diseases. All certified seed must exceed 85% germination, however the seed of most public and private varieties exceeds 90% germination. Thus, seed of public and private varieties offered for sale is assured to be high in purity and germination.
Farmer saved seed may also be of high quality,
but many times is not. The reason is that farmer saved seed may or
may not be genetically pure. If the variety has been grown for several
years, it will probably be contaminated with seed of other varieties and
may not have the original disease resistance and yield potential. In addition,
farmer saved seed will usually fall into one of the following categories:
run. No seed cleaning, seed treatment or testing prior to planting.
Thus, the only quality check is "It looks good". This is not recommended
and could result in replanting due to poor germination or serious spread
of weeds, such as annual ryegrass, cheat and hairy chess, which have become
major weed problems in wheat fields in recent years.
cleaned. Seed is cleaned by a custom conditioner, but not treated.
This seed may on may not be tested for germination and is not usually tested
for purity and weed seed contamination. This procedure is risky,
because the seed may still contain unknown weed seeds (even though cleaned),
since it hasn't been tested for purity and it will have no protection against
seed-borne (i.e. loose smut) or seedling diseases.
cleaned, treated and tested. If farmers are planting their own saved
seed, this procedure is recommended. This will provide the basic
seed quality information and aid in planting decisions. This procedure
does not insure varietal purity, however.
The cost of a purity, germination and seed
count test at the Seed Laboratory, Division of Regulatory Services, University
of Kentucky is $15.00. Individual tests costs are: seed count - $4.00,
germination- $7.00 and purity - $5.00. If a farmer is uncertain about
weed seed contamination and germination of bin run seed, sample the bin
and have it tested.
Legal infringement and liability:
Most public and private wheat varieties
sold and planted in Kentucky today have been protected through the US Plant
Variety Protection Act (PVPA, 1970, 1994). This means that seed of the
variety may not be reproduced, sold or offered for sale without the permission
of the owner.
The original PVPA (varieties protected prior to April, 1995) allows the farmer to save only as much seed of a protected variety as needed to plant a crop on his (her) holdings (owned, rented or leased land). If planting intentions change, the farmer may sell the remaining saved seed, but the amount planted plus the amount sold cannot exceed the amount required to plant his holdings.
In 1994 the Act was amended allowing the farmer to save enough seed of a variety protected after April, 1995 to plant back on his (her) own holdings, but none of the saved seed may be sold without permission.
Under both the original and amended Plant
Variety Protection Act, it is an infringement to clean, bag or stock farmer
saved seed if the quantity exceeds what the farmer can legally save for
So, what implication does Plant Variety Protection have for Kentucky farmers??
Since most wheat varieties are protected,
farmers can save seed and plant it on their own farm without violating
the owner's rights under PVPA. If the variety was protected under the original
PVPA (prior to1994), farmers can only sell seed to their neighbors if his
original planting intentions changed and then the total seed sold and planted
cannot exceed the amount required to plant his holdings.
Example, using a 2 bushel per acre seeding
rate, a farmer with a 500 acre farm could save a maximum of 1000 bushels
for planting. If his planting intentions change and he only planted 150
acres he could sell only the remaining 700 bushels.
If a variety was protected after the 1994
amendment, the farmer can only save seed for planting on his own holdings.
If the seed is sold, offered for sale, or title to or possession of the
seed is transferred for reproductive purposes, without authorization of
the owner of the variety, it is an infringement of the Act. Thus, farmers
cannot legally sell or trade seed of a variety protected (post 1994) to
A partial list of those public and private
wheat varieties protected before and after the 1994 amendment to PVPA is
shown below. To be certain regarding Plant Variety Protection of a public
or private variety the farmer should check with the owner, seed dealer
or Kentucky Seed Improvement Association.
Farmers saving their own wheat seed can
potentially save some input costs for planting in the fall of 1999. However,
farmers should only plant seed of a known variety that has been cleaned,
treated and tested. Compare the total costs and potential returns to purchasing
high quality certified seed of public or private varieties. Be careful
that by saving a few dollars you aren't risking liability by violating
Plant Variety Protection laws or planting seed with weed seed contamination
or disease infection.
Partial list of those wheat varieties protected
under the Plant Variety Protection Acts (1970, 1994 (See statement at bottom
Coker 9474 Agripro Elkhart
FFR 555 Agripro Foster
P2552 Agripro Mason
P2684 Agripro Patton
P2548 Coker 9663
|ST Advantage||Additional ST Costs||Additional NT Costs|
|Test||Managed by:||Yield (bu/a)||Value||Residue Mgmt||Tillage||Seed||Herbicide||N Fertility||Net ST Benefit|
|----------------------------------------------- $/A ----------------------------------------------------|
1. Abbreviations: ST- some tillage; NT-
no-tillage; OC - Miles Opti-Crop; UK - University of Kentucky, and WT -
2. Expenses which were in common were not
considered in this analysis, as the goal of the project was to compare
economic advantages of the two tillage systems.
3. No economic credit was given for the
long-term economic advantage likely to result from use of no-tillage methods
(through the conservation of topsoil).
4. No economic credit was given for the
potential benefits of no-tillage methods to rotated corn and soybean crops.
5. We assumed that neither test weight
nor harvest moisture were influenced by tillage system.
6. Both ST and NT were managed to optimize
their profitability rather than to obtain the highest possible yields.
7. Specific practices employed (for example,
the type and number of tillage passes) are shown in detail in the attached
summaries of individual test locations.
8. Each location included two varieties
and two replications. Calculated yield differences between tillage systems
are assumed to represent real differences.
9. In five of the above tests, the later
maturing variety produced higher yields than did the earlier maturing variety
(within a given location). Rather than picking the better variety to paint
this economic collage, we averaged across the two (to make our conclusions
10. This data should be interpreted with
some caution, as environmental conditions in coming seasons could clearly
affect the outcomes of the two tillage systems. (However, some management
considerations may have already helped buffer NT wheat from winterkill;
for example, none of these 7 tests were planted in early October, and that
may have helped account for the similar survival of most NT tillers in
the face of a severe spring freeze in early March, 1998).
11. In 1998, we used a market price of
$2.90/bu. The income deficiency payment for 1998 tests brought the value
of the 1999 crop to $2.80/bu.
12. No adjustments were made for differing
speed of operations; for example, ST was not penalized for slightly slower
combining, nor was NT penalized for slower speeds while drilling the crop.
For More Information, Contact:
Dottie Call, Wheat Group Coordinator
UK Research and Education Center
P.O. Box 469, Princeton, KY 42445
Telephone: 502/365-7541 Ext. 234