Fungicid seed treatments have come a long way. Have they come far enough to replace in-furrow fungicides? “We have some good seed treatments,” says Melvin Newman, University of Tennessee plant pathologist, when asked the question. “These Quadris-based fungicides are doing a good job, and they're putting enough product on to do some good.
“But if you ask me what's the best thing you can do for your cotton crop, I'm going to say a full rate of an in-furrow fungicide is still the best thing because you're putting down 10 times the fungicide. Seed treatment is treating the seed. An in-furrow treatment is treating the soil.”
Newman says he can understand how farmers may be tempted to put everything on the seed and go. “It's hard to argue when it comes up and looks good.”
Newman stresses that farmers “shouldn't just accept carte blanche a no-tank, no in-furrow approach” to cotton planting. “If the weather turns out right and we optimize everything, I don't have much of a problem with the approach, as long as the farmer knows he is accepting a risk for a little less expense and a little convenience.”
Optimizing begins with planting good, quality cotton seed with a cold test of 70 to 80 or higher, according to Newman. “Farmers can get cold test data from seed companies and dealers. If it's below 60, that's a big indication of some trouble. Get an adequate overcoat seed treatment. But there has to be enough of the seed treatment applied.
“Not using a soil-incorporated herbicide (as you would with herbicide-resistant cotton) can be a plus for the cotton plant,” Newman added.
When should you use an in-furrow fungicide? “If you have some cold, bottomland, a small seed or one that isn't real good on the cold test, and you're planting early, that's when I would use the maximum rate of an in-furrow fungicide. A lot of our west Tennessee farmers are in that situation.”
Newman noted that west Tennessee cotton producers planted a lot of their cotton acreage to Paymaster PM 1218 BG/RR in 2002, and it is one of the largest-seeded varieties on the market. The pathologist added that smaller-seeded varieties “just don't have the energy that the bigger-seeded varieties have.”
Growers can reduce costs with in-furrow fungicide by keeping an eye on the weather and soil temperatures, Newman noted. “If we're planting in cool soils, start out with a combination for both Rhizoctonia and Pythium. As the soil dries and warms up, drop out the Pythium control and go straight with the Rhizoctonia material. You can cut your costs way down just doing that.”
The 2002 season was as big a test of a tankless planting system as you could ask for, noted Newman. But in the end, things turned out well for west Tennessee growers.
“We had a lot of replanting. I estimate 25 percent to 40 percent of our acreage in west Tennessee and the highest seedling disease loss in my 30 years of experience, a 20-percent loss. But we still made a high yield. Cotton rebounded pretty well.”