What is in this article?:
• The old yield-robbing foe that has popped up with too much regularity from Georgia to Mississippi over the past three years is white mold.
• Caused by the fungi Sclerotium rolfsii, white mold, or Southern stem rot, as it is often called, came on late in the season and kept statewide yields across the belt from setting the record yield bar even higher.
UNIVERSITY OF GEORGIA Plant Pathologist Tim Brenneman explains early season peanut disease control.
Early emergence banding
As part of that effort he tried a system called ‘early emergence banding’ in which he uses Proline in a 40 gallon over-the-top spray, concentrated in a 4-5 inch band.
That volume of water in the band is equal to 300-400 GPA broadcast, and was designed to force a good volume of fungicide down to the root system of young peanut plants where CBR infections begin.
“Though our target was CBR, our initial test in 2010 showed dramatic reductions in white mold with one spray of Proline at 21 days after planting (a time when we normally do not even spray fungicide).
“Additional trials in 2011 showed significant yield increases. Results in 2012 were more mixed, probably due to the cooler early season temperatures, but several trials again demonstrated a strong yield response,” the UGA researcher says.
In addition to the target pest, CBR and white mold, the use of banded sprays early in the season also showed good control of leafspot, and lower spray volumes (10-20 gallons per acre) have done just as well as 40 GPA.
“We have learned more about how several different fungicides work in this type of early application, but there are still questions about use on twin row peanuts, spray volumes, etc.
“The main questions regard how to incorporate these early sprays in full-season fungicide programs to give the best economic return, and how they actuallycompare to simply broadcasting similar fungicides early in the growing season, Brenneman says.
“Either way, preventing white mold before it begins is an important step toward obtaining the full potential of new high-yielding, but disease-susceptible cultivars like GA-06G,” he adds.
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