Figure 4. Corn seedling blight
Damping-off and seed decay. Germinating corn seed can be attacked by several seed-borne and/or soilborne fungi. Pre-emergence and post-emergence damping-off caused by fungi is most common in poorly drained, cold soils. Seed rots and seedling blights are commonly caused by Pythium and Fusarium species, and may be caused by Penicillium and Bipolaris species. All of these fungi can rot seed prior to germination. Infected seedlings typically show a marked softening of stem tissue at the soil line.
Kernels with surface cracks caused by mechanical harvesting are especially susceptible to seed rots caused by soilborne pathogens. Broad spectrum, protectant-type fungicides are highly recommended for both corn and sorghum, especially when early planting in cold, wet soils is attempted. Pythium seedling blight is most significant under these conditions. Most seed corn companies treat their seed prior to bagging. However, planter-box formulations of these materials are available for use by the grower on untreated field, sweet, and popcorn seeds.
Figure 4. Corn seedling blight