Tar spot is caused by a fungus called Phyllachora maydis that can spread throughout corn fields in the Midwest. This disease was first found in 2015, but has quickly spread throughout Iowa, Illinois, Indiana, Minnesota, Wisconsin, Ohio, Michigan, and Missouri.
Certain areas around the Midwest have received significant hail damage to crops in recent days and weeks. After damage has occurred it is important to wait at least 5 days before assessing. This gives the crop the appropriate time to regrow and allows you to more accurately evaluate stand loss.
The delayed planting season makes it easier for pests like black cutworm to invade. Black cutworm, the most damaging cutworm species in corn, is a migratory pest that shows up in the spring with storms.
Stand establishment of corn and soybeans is the combined result of several things such as seed quality, planting standards, soil conditions at planting, and weather patterns 24-48 hours after planting. Evaluating stands involves determining two things: stand quantity (population) and stand quality (number of full ears at harvest compared to planting population).
Managing corn rootworm beetles can be done several different ways. Crop rotation is one way to interfere with the corn rootworm life cycle by using a corn/soybean rotation.