What is in this article?:
- Disease control ranks at No. 4 in Keys to Peanut Profitability
- White mold is special case
- Control begins with rotation
• Great strides have been made in peanut disease control in recent years, especially through the development of genetically improved varieties. But as producers look ahead to the 2012 production season, white mold looms large as a serious disease threat.
White mold is special case
White mold is a “special case” for peanut producers compared to other soil-borne diseases, says Kemerait.
“Maybe one-third of growers have seen CBR in their fields. Both CBR and white mold are serious diseases, and both cost growers in terms of a significant amount of worry, and of lost yields. Also, the symptoms of the two diseases can appear very similar.”
The diseases are spread by sclerotia or fungal “seeds”, he says. They both survive in the soil, waiting for the next peanut crop.
“Sclerotia attack the part of the plant that is closest to the soil. They’re called soil-borne because their survival structure and fungus are growing in the soil.”
It’s important, he says, that growers understand how CBR and white mold are different from one another.
“While environment is important with white mold, it’s even more important with CBR. If we have hot, dry conditions or a hot spring, we won’t get much CBR.
“It is driven by cooler temperatures. Early infection by the CBR pathogen occurs on the developing root system. White mold likes warmer temperatures. Even if it’s cool during the first part of the season, white mold will jump up later in the year. White mold needs oxygen, and it can be the biggest problem around the crown of the plant.
“While both CBR and white mold are severe on a field-by-field basis, I would rather have a bad case of white mold any year than a bad case of CBR. CBR survives longer in the soil. Also, managing CBR is much more difficult and the yield losses can be as bad, or worse, than white mold. On a field-by-field basis, I believe CBR is worse than white mold.”
However, every grower has to fight white mold, says Kemerait. The disease is found over a much greater part of the world, and it’s found over a greater part of the Southeast.
“If you have soybeans, you may have white mold, and it’ll even go to vegetables. So the distribution is larger than with CBR.”
Environment also is a big factor, says Kemerait. “We will always have conditions at some time of the year that will be favorable for white mold outbreaks. It’s not a matter of if you’re going to have it, but when you’re going to have it. Hot temperatures earlier mean an earlier epidemic, but it’s going to eventually get hot in the South.”
CBR infects a limited number of plants, including soybeans, coffeeweeds and peanuts. White mold, on the other hand is found on 180 to 200 species of plants. Because of this, white mold is likely to affect your location in one way or another, he says.