Scouting for soybean seedling diseases in Ohio

By Horacio Lopez-Nicora, OSU Soybean Pathologist and Nematologist, Adapted from C.O.R.N. 2025-14

Persistent cool and wet weather across Ohio has created ideal conditions for soybean seedling diseases. As we move through the early stages of the growing season, it’s critical to scout fields for symptoms and signs of seedling blights and root rots that can compromise stand establishment and yield potential.

Soybean seedling diseases are often difficult to diagnose in the field because symptoms can overlap with abiotic stress or insect injury. However, early identification is key to managing these issues effectively. Common culprits to watch include Pythium seedling blight, Phytophthora root rot, Fusarium root rot, and Rhizoctonia seedling blight.

To identify Pythium seedling blight, growers should look for water-soaked, mushy seedlings with poorly developed roots. Pythium thrives in cool, saturated soils.

To identify Phytophthora root rot, the symptoms include mushy stems and stunted or wilted seedlings. Unlike Pythium, Phytophthora prefers warmer soils but still benefits from wet conditions.… Continue reading