(July 2008) Common in soybean growing areas in the southern United States, frogeye leaf spot has been making its presence known in 2008, especially in irrigated fields with elevated moisture levels, non-resistant soybean varieties, and fields that have had frogeye problems in the past, says Darrin Holder, CROPLAN GENETICS® seed and AgriSolutions™ brand regional agronomist.

Frogeye leaf spot is characterized by "eyespots" on the leaves with gray or tan centers and purplish-brown margins. Eventually the entire lesion turns black. Frogeye can also grow on stems and pods. Affected plants may have premature leaf drop. The disease may be seedborne or airborne.

One effective preventative management treatment is the application of a fungicide such as Headline®. Not only is it effective against frogeye leaf spot, but it is also labeled for use against other soybean-prone diseases, such as Cercospora blight, anthracnose and Asian soybean rust.

"Headline® needs to be applied at the R1 to R3 growth stages, or prior to any visual evidence of a disease being present," Holder advises.

Another option is Quilt® fungicide, which has both preventative and curative properties. Per label recommendations, Quilt® should be applied at the R3 growth stage (early pod set when pods are 1/8-1/4 inch long) and 14 to 21 days later at growth stage R5 (pod fill).

"Whatever you use, coverage is crucial because the fungicides out there are not systemic," Holder adds. "You need cover the entire plant, and it's a good idea to use a tank mix containing PowerLock® for its surfactant and drift-reduction properties."

Other control measures include planting resistant varieties, planting disease-free seed and rotating crops after an infection. Infected fields should not be planted back with soybeans for at least two years.

To check out CROPLAN GENETICS® soybean varieties in fields like yours under local conditions, visit the Answer Plot® site in your area. Soybean varieties are organized by genetic families, so you can compare the differences firsthand and identify the precise soybean seed solutions for your fields. To locate the Answer Plot® site nearest you, visit the AnswerPlot.com site.