37 Tips for Identifying Four Common Problems in Soybeans It’s important to note that many soybean diseases can cause similar symptoms, and accurate diagnosis may require laboratory analysis or consultation with an expert agronomist. Contact your local Maizex dealer for assistance in identifying issues in your fields. Soybean Cyst Nematode (SCN) is a microscopic roundworm that can cause significant yield loss. • Infected plants may appear stunted and yellowed, with reduced root growth. • Small white or yellow cysts can be found on the roots of infected plants that are inspected. • Genetic resistance, field rotation, and specific seed treatments such as Saltro® or TrunemcoTM can help to prevent yield loss. Phytophthora root and stem rot is a water mould that can cause root and stem rot in soybean plants. It is a growing problem in regions across the country. • Infected plants may appear stunted and yellowed, and leaves may wilt or drop. • Seedling plants may dampen off. In older plants, look for patches of stunted, wilting, or yellowing plants in the field. Lesions may be found starting at the soil line and extending up the stem. • Rotation, varietal selection, and stacked seed treatments including Vayantis or Lumisena are key management strategies. White mould, Sclerotinia, is a fungal disease that can cause the wilting and death of soybean plants, particularly under cool, humid, or wet conditions. • Infected stems will become soft and watery and will show white, fluffy growth on stems or branches with leaves turning yellow or brown. • Look for patches in the field, with plants that are sinking from the surrounding canopy and, if progressed, with dead upright stems. Check for white mycelial growth on the stem and leaves starting lower in the canopy. • Variety selection and using low plant densities and wider rows to improve air circulation are sound management strategies. Maizex tests extensively for white mould tolerance in trials across the country. Sudden Death Syndrome (SDS) is a fungal disease that can cause yellowing and wilting of the leaves, reducing yield in infested areas. • Plants start to show definitive speckling turning to dark brown or black patches between veins. Stem may show internal discoloration. • Other symptoms include root rot, premature defoliation, and reduced yield. Look for yellowing and wilting of the leaves in a pattern that starts at the base of the plant. • Genetic tolerance and the use of specific seed treatments including Saltro in high-pressure areas are key practices to maintain yield potential.