Corn Smut Biology and Disease Cycle
Fungal infection occurs through silks and into the kernel early in development. The fungal mycelium causes the kernel to enlarge and completely colonizes the kernel tissue. Thousands of black to brown spores, known as teliospores, develop within the gall. Once teliospores are mature, the gall bursts, and spores are exposed to the environment and dispersed by wind or rain (Figure 2). The teliospores can infect nearby corn leaves and stalk tissue during the growing season. Furthermore, teliospores overwinter in the soil and crop residue and are the inoculum source for the following season.2
Management
Because corn smut is rarely economically significant in grain cropping situations, direct management actions are often unnecessary. No chemical control options are recommended for corn smut management; however, resistant sweet corn varieties have been developed and may be deployed.
In addition to genotype, any factor affecting corn pollination can affect corn smut disease development. It has been demonstrated that adequate pollination limits pathogen progression and reduces disease incidence, severity, and gall number, among other variables.3 In addition to poor pollination, a high incidence of corn smut could also indicate that young ear tissues were exposed to mechanical damage from wildlife, hail, or severe insect pest pressure. If this is the case, other ear rot diseases may also be present, some of which may be mycotoxigenic, causing harm to humans and animals. If this is the case, it is essential to scout these fields to identify the different corn ear issues correctly.
Source : psu.edu