Damping-off caused by Pythium . Phytophthora stem rot. Seedling disease caused by Rhizoctonia exhibits different symptoms from those caused by Pythium and Phytophthora . Seedling blight by Rhizoctonia normally appears when the weather becomes warm. Unlike Pythium and Phytophthora damping-off, stem discoloration by Rhizoctonia is usually limited to the cortical layer of the main root and hypocotyl.
Infected stems remain firm and dry.
Typical symptoms are localized brown to reddish brown lesions on the hypocotyl. What to do if you find seedling diseases . If no significant stand reduction has occurred, you do not need to be concerned if the disease is Pythium or Rhizoctonia damping-off. Consider using a variety with a better resistance gene for the next soybean crop. Although replanting is not always needed with stand reduction, root rot, especially Rhizoctonia root rot, may follow stand reduction in plants that are infected but not killed as seedlings.