Incidence of Stenocarpella maydis Ear Rot of Corn Under Crop Rotation Systems

The efficacy of crop rotation in reducing corn ear rot caused by Stenocarpella maydis in reduced and conventional tillage systems was determined over five and four seasons, respectively, at two sites in South Africa. Stenocarpella ear rot and S. maydis was isolated from kernels more frequently in monoculture corn and crop rotation where corn was planted for two consecutive seasons than where monoculture corn was interrupted by a rotation crop. Surface stubble mass, and consequently inoculum pressure, were affected similarly by crop rotation. Positive linear relationships were recorded between Stenocarpella ear rot incidence, surface stubble mass, and pycnidial counts. Wheat, soybean, and peanut were the most effective, and sunflower the least effective, rotation crops for reducing S. maydis ear rot.