What is in this article?:
- White mold remains the No. 1 disease pest in Southeast peanut production.
- Since 1994, more tools have become available for the controlling the disease, including chemicals and new application methods.
- Producers need to guard against building resistance with certain fungicide classes.
WHITE MOLD REMAINS the No. 1 disease pest for Southeastern peanut producers, but more tools are available now than ever before to control it.
Application techniques change
One of the most difficult factors in controlling white mold is how to get the fungicide through the dense canopy of leaves to the real target- the limbs and crown of the plant, says Kemerait. In 1994, growers broadcast their sprays, spraying every 14 days and using increased pressure to get the spray where it needed to be. Adds Kemerait, “Growers throughout the southeast have really benefitted advances in application technology from Dr. Tim Brenneman’s program at the University of Georgia in Tifton.”
“A relatively new innovation – if we can get growers to get up early enough or stay up late enough – is to spray peanuts at night. At nighttime, the leaves of the peanut plant are folded up and you get better spray deposition. You get the fungicide to the crown of the plant. And when those leaves open during the daytime, they are protecting the applied fungicide from ultraviolet degradation.”
Yield differences in some fields between daytime and nighttime spraying have been as much as 1,000 pounds per acre, he says.
In 1994, says Kemerait, growers began their fungicide spray program for white mold 60 days after planting.
“They still do that, but as of 2011-2012, we began recommending that growers who had white mold problems should start earlier. Spraying a young plant sets the foundation for a good white mold program. Where white mold is severe, we’ve seen that you can get season-long benefits from starting earlier. It’s easy for me to say that you need to put a 6-inch band over 21-day peanuts or a 10-inch band over twin rows, but that’s not easy when you’re running 3 to 6 mph over a field. But the opportunity is there. Early emergence banded applications three to five weeks after planting can be very important where white mold is a problem.”
While white mold was not as severe in 2014 as some predicted, growers still saw benefits from early emergence applications, says Kemerait.
“The cool temperatures last year precluded much early season white mold. If you’ve had white mold problems and you’re thinking about making early emergence applications, look at the strategies for putting it out and anticipate the weather patterns. A cooler early season means you probably won’t have as much of an early season white mold problem.
“If you’ve had a problem with white mold, and you’re not set up to do the early emergence or in-furrow application, we already have the tools to start a white mold program at 40 to 45 days; perhaps by broadcast applications of tebuconazole mixed with your leaf spot fungicide. Then, you can bring the big guns – the more powerful, newer fungicides – at 60 days in your block program.”