How do you translate the value of resistance into production practices?
By Amanda Huber
Peanut Rx incorporates those production factors that affect diseases in a peanut crop, starting with the variety planted. Varieties today have improved resistance to nearly every disease and, in the case of Tifguard, excellent resistance to nematodes. But what is the value of that improved resistance and how does it translate into value for the producer?
Bob Kemerait, University of Georgia Extension plant pathologist, says if producers use Peanut Rx or the peanut prescription, the difference in point values translates into potential differences in production practices.
Translating Points Into Practices
“Compare Georgia-06G and Georgia-07W: For spotted wilt resistance, they are the same; leaf spot resistance, they are the same. However, we know that Georgia-07W has twice the resistance for white mold as Georgia-06G. How does that translate into value for you?
“The difference is the same as having an extra year of rotation away from peanuts or soybeans. This difference is the same as allowing for earlier planting date without compromising white mold control. This difference negates the effect of a high plant stand on white mold control, and this difference negates the impact of tillage and irrigation as far as impact on white mold.”
According to Kemerait, that is what the point value is translated from numbers into practices.
“The index is not just about numbers,” he says. “It’s about finding the equivalence in production practices, be it a year of rotation or irrigation.
“If you plant a more resistant variety, but you treat it exactly the same, using the same fungicide program as you would a less resistant variety, what are you buying? You are buying added insurance,” Kemerait says. “You may not need that insurance, but by treating it the same way, you are not putting value on the white mold resistance.”
Translating Value Into Savings
For tomato spotted wilt and cylindrocladium black rot, varietal resistance has been readily adopted, but primarily because it is the only way to combat those diseases. A problem such as nematodes provides a different example.
“Tifguard has near immunity to root-knot nematodes, but growers wonder if they could use Telone or bump the rates up on Temik when planting 06-G,” Kemerait says.
“You can do that, but by choosing a variety that has to be treated with a nematicide, you are increasing your cost of production anywhere from $30 to $150 an acre simply in the investment of the nematicide. Then, you are assuming that nematicide will bring your yield up.”
From a researcher’s standpoint, you owe it to yourself to consider using the variety Tifguard when you have nematode problems.”
With improved resistance and the prescription fungicide programs, the goal of growers should be to make sure the right amount of fungicide is used to maintain yields and maximize profit in return and not using more fungicides than is needed, Kemerait says.
“The varieties you select are a key component in what your risk is. Improved resistance should be of tremendous importance in how you develop a disease management program.”
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Possible Nematicide Shortage
BY BOB KEMERAIT, UGA EXTENSION PLANT PATHOLOGIST
The nematicide, Temik, may be limited this year. Bayer CropScience, maker of Temik 15G, is trying to put a re-vamped production facility in West Virginia back on line. The basic ingredients for Temik are made at this facility. Residents in the area around the plant have filed a law suit to keep the production facility closed.
A judge was expected to rule on the matter in late March. If the judge rules in favor of re-opening the plant, the supply of Temik should not be too affected; however, do not expect to find the “corn cob” formulation this year, only the “gypsum” formulation.
If the judge rules against re-opening the plant, then the only Temik will be what is already in distribution.
Hopefully, Temik will be available in 2011. If the worst does occur, options for growers include the following:
1. Tifguard variety, which is nearly immune to peanut root-knot nematodes
2. Telone II fumigant + Thimet/phorate for thrips control
3. NemOut biological nematicide could be useful in some situations, but overall efficacy is yet to be determined.
4. Enclosure is a fungicide that is now available as a nematicide, but efficacy is yet to be determined.