What is in this article?:
- Placing a value on disease-resistant peanut varieties
- Investing in yield
• What’s the true value of a peanut variety’s resistance, from the viewpoint of growers?
• Tomato spotted wilt virus (TSWV) resistance certainly matters, and breeders have spent considerable time breeding resistance to other diseases.
• In the past five years, many disease-resistant varieties have been phased out because they were not widely adopted.
Investing in yield
Why are growers willing to adopt TSWV and CBR resistance when they hesitate on others? The tools for managing TSWV and CBR are less reliable than tools for managing leafspot and white mold. So you invest in yield, and you say you’ll buy a fungicide program that compensates for the reduction in resistance.”
If you plant a more resistant variety but you treat it exactly the same as a less resistant variety, you’re buying added insurance, he says.
“With Tifguard, we have absolute immunity to the root-knot nematode, and growers are considering instead using Telone or bumping up their rates on Temik and planting GA-06G. 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 per acre to $150 per acre simply in the investment of a nematicide. And then you’re assuming that the nematicide will bring up your yield of GA-06G.”
From a research standpoint, it’s a no-brainer between GA-06G and Tifguard if you’ve got nematodes, he says. “From a grower standpoint, there might be concerns over things like peg strength, but if you’ve got nematodes, you owe it to yourself to consider a variety like Tifguard.”
Comparing GA-06G and GA-07W, as far as TSWV resistance, they’re the same, he says, and as far as leafspot resistance, they’re the same.
“But we know that GA-07W has twice the resistance to white mold as GA-06G. This difference is the same as having an extra year of rotation away from peanuts or soybeans. It’s the same as allowing for an earlier planting date without compromising white mold control. This difference negates the effect of a high plant stand, and it negates the impact of tillage and irrigation as far as impact on white mold. That’s the value of something like that. When you look at those differences in the Peanut Rx, that’s what the value is. It’s not just numbers — that’s how you can relate it to what you’re doing.”
With greater resistance now available to growers, the goal of prescription fungicide programs is to make sure you use the right amount of fungicide to maintain yields and maximize profit on return, says Kemerait.
“The variety you select is a key component in what your risk may be. In Georgia, seven spray programs are what we’ve normally been accustomed to. By using this Peanut Rx — by using a good variety, a good rotation, and by choosing resistance, you can go to a low-risk or moderate-risk situation, and in doing so, you can go from a seven-spray program to a five-spray program. Fewer sprays mean less money for fungicides and less cost.”
Improved resistance in varieties should be an important consideration in how growers develop a fungicide program or a disease management program. When you’re deciding between varieties, understand what the benefits are for the resistance program, says Kemerait.