Author: Darcy Telenko There are a number of fungal soybean diseases that can greatly impact seed quality. In Indiana, the most common are Phomopsis seed decay (Phomopsis spp.), Cercospora purple seed stain (Cercospora kikuchii); Frogeye leaf spot on seed (Cercospora sojina); Anthracnose (Colletotrichum spp.); Downy mildew (Pernospora manshurica); and various other secondary fungal invaders of injured pods including Alternaria, Fusarium, Cladosporium, and Penicillium. The tables below provides several descriptive characteristics to begin the diagnostic process and choose appropriate management recommendations. It is important to note, however, that although Purple Seed Stain is easily identified by the ‘signature’ purple symptom on the seed, accurate diagnosis of most of the fungal diseases on seed requires microscopic assistance offered by the Purdue Plant and Pest Diagnostic Laboratory (PPDL). The diversity of symptoms that can be observed on diseased soybean seed is shown in the example in Figure 1. In this image, all of[Read More…]
