PHOTO BY BREWTON AG RESEARCH UNIT
Premature defoliation due to leaf spot diseases is shown in the non-treated control at left. Chlorothalonil was used on the peanuts at right in a fungicide trial at the Brewton, Alabama, Agricultural Research Unit.
Late-Season Decisions Fungicide applications at this point often involve levels of disease and projected digging date. By Amanda Huber
L
ate peanut season may seem like a race to the finish. Unfortunately, it is often a race between diseases, such as leaf spot, and the crop reaching optimum maturity. The dilemma is whether to apply another fungicide treatment to keep leaf spot from defoliating the crop, while also reducing the bottom line, or let the crop finish out with no added protection, saving that input cost. Fortunately, Extension specialists offer guidance with the late-season disease and insect problems.
“If leaf spot is not a problem, nor white mold, then you may not need the sprayer in the field again. If leaf spot is in the field and not too severe, you might consider one last application,” Kemerait says. “If you have lost 25% of peanut leaves, anticipate digging within two weeks, regardless of maturity. If you have lost 50%, you have a week to 10 days max.” Finally, he says, if you have lost 75% or more – dig immediately, as the pods are likely dropping off now.
If, Then Leaf Spot Scenarios University of Georgia Extension plant pathologist Bob Kemerait offers a series of “if, then” questions and answers for producers on a progression of leaf spot and spraying or digging. If you are a few weeks out from digging, he says, continue to assess your field for disease.
Factor In Tropical Weather Threats Alabama Extension plant pathologist and Auburn University assistant professor Amanda Strayer-Scherer offers similar endof-season suggestions for peanut producers as they begin to plan for digging. “Leaf spot diseases can severely defoliate peanuts if not con-
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THE PEANUT GROWER • JULY 2022
PEANUTGROWER.COM
