Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Several leafspots are beginning to appear on susceptible soybean varieties. These include Septoria leafspot as well as downy mildew. If you have good plant growth and a dense canopy after the recent rains and if the fields are irrigated both diseases could be present. Neither disease is thought to be yield limiting here on Delmarva.
Downy mildew on soybean showing the yellow irregular spots on the upper surface of the leaf
Closeup of lower leaf surface showing the small tufts of tan fungal growth of the downy mildew fungus that could be seen with a 10X hand lens.
Last chance to register for the upcoming Soybean Cyst Nematode Workshop, August 3. There are still spots open if you want to attend. See the announcement at the end of the newsletter.