Three diseases were prevalent in Iowa soybean fields this year:
Rhizoctonia root rot, white mold, and brown stem rot.
Rhizoctonia root rot was a major mid-season disease problem,
while white mold and brown stem rot were prevalent later in the
season because of cool weather in August and September. White
mold also was more widespread than in 1994. Recently I've been
getting two questions: - 1) What can I do at harvest to manage
soybean diseases?, and - 2) Does tillage help reduce the risk of
these diseases? These are good questions to ask at this time of
year because certain soybean diseases can be spread during
harvest, and fall tillage can break the cycles of many diseases.
You can minimize certain disease problems in the next soybean
crop by following proper harvest and tillage practices with your
current crop. In this article, I will review the effects of
these two practices on each disease. Rhizoctonia root rot The
fungus that causes this disease grows and survives in the top 2
inches of the soil surface.