By Clint Thompson
The Georgia Peanut Commission and University of Georgia (UGA) Extension caution producers about disease management with harvest season approaching.
Bob Kemerait, UGA Extension plant pathologist, discusses white mold and leaf spot, which could be problematic with increased rainfall in certain areas of the state.
“This change in weather we’ve had, it’s almost like a light switch in South Georgia. Since about July 2, we went from extremely hot and dry, which brings its own problems in crop production diseases to extremely wet in a lot of areas. That’s going to cause problems for our growers in a number of different ways,” Kemerait said.
Conditions Ideal for White Mold
“Prior to the rains, that hot weather certainly brought on white mold. It flourishes in hot weather, especially warm nights. Now with the abundant moisture, our growers really need to be prepared and vigilant for white mold problems and leaf spot problems.
“My recommendation to growers is to recognize we’re in perfect conditions for leaf spot and for white mold and recognize that the single most important thing you can do is to be timely with an (fungicide) application. That often times requires footsteps in the field and being prepared to do that. If you get behind on white mold or leaf spot this year, with the conditions we have and the delays you could have getting into the field, you may not ever catch up.”
White mold is often the top cause of the loss of peanuts due to disease in a season. Sclerotium rolfsii, the causal agent of white mold, is a fungus that remains in the soil between cropping systems and waits for the next susceptible crop to be planted.
The disease becomes more problematic when growers fail to use proper crop rotations. Growing peanuts behind peanuts is highly discouraged because of diseases like white mold.
Leaf spot causes the peanut plant’s leaves to wither, turn yellow and fall off. It can also form lesions on the stem and other parts of the plant.