Higher soybean prices may make yield-enhancing crop inputs attractive – but before using a foliar fungicide – DuPont Pioneer Senior Research Manager Steve Schnebly says it’s important to scout and determine the type of disease or diseases present. Scouting should be done prior to the R3 growth stage – especially if the weather has been rainy or humid – according to Schnebly – since these conditions are most favorable to foliar diseases. If these conditions continue – he says these diseases spread faster – making scouting vital to help reduce damage. He specifically notes two diseases to scout for this summer – frogeye leaf spot and septoria brown spot. Symptoms of frogeye leaf spot appear as light gray lesions surrounded by dark borders that may coalesce to farm larger irregular spots on leaves – according to Schnebly. As for septoria brown spot – he says growers should look for small, angular, red-brown spots on unifoliate leaves – which can be more pronounced on lower leaf surfaces – though they also develop on upper leaf surfaces. If left untreated – frog eye leaf spot can significantly reduce yields and septoria brown spot can cause economic losses.
To help manage both of these diseases – Schnebly recommends a foliar fungicide application if disease levels exceed thresholds – which can be found by contacting your local DuPont Pioneer agronomist or state extension specialist. Both diseases can be easily controlled – Schnebly says – with a combination of good crop scouting, good management and good variety selection. For more information – visit www dot pioneer dot com (www.pioneer.com).