Physoderma Brown Spot and Stalk Rot of Corn Caused by Physoderma maydis in Iowa

Abstract

Physoderma brown spot (PBS) and stalk rot (PSR) of corn is caused by Physoderma maydis. The prevalence of PBS in the U.S. Corn Belt has increased within the past decade. In Iowa, in 2013 and 2014, PSR with associated stalk breakage was reported from numerous fields in western and northern Iowa. In some fields, up to 80% of plants in a field were affected. The reasons for the outbreak of PSR are unknown, although abundant rain during early growth of the corn likely played a role. Accepted for publication 2 April 2015. Published 4 May 2015.