Mercer County farmers are seeing a mixed picture as corn and soybeans move through the middle of the growing season.

Mercer County OSU Extension Educator Ryan McMichael said some early-planted corn fields look strong after getting into the ground before the heavier spring rainfall. Other producers dealt with poor stands, delayed planting and, in some cases, the need to replant.

Later-planted soybeans are beginning to fill out, but wet conditions created challenges for weed control. McMichael said some farmers were unable to apply pre-emergent herbicides and are now relying more heavily on post-emergent applications.

Farmers are also being encouraged to begin scouting corn fields for disease, including tar spot. The disease has been confirmed in parts of Ohio, although McMichael said he has not received reports from Mercer County or neighboring counties.

Tar spot appears as small black spots on corn leaves and can significantly reduce yields if it becomes established. McMichael said farmers should check whether the spots can be scraped from the leaf. If they come off easily, they may be insect waste rather than tar spot.

McMichael said timely scouting is important because fungicide applications are most effective when diseases are identified early.

It remains too early to accurately estimate yields. Some corn is beginning to tassel, while soybeans in several fields have reached the flowering stage. McMichael said timely rainfall will be important as corn moves through pollination and begins developing ears.

Producers are also reminded to follow pesticide labels and make sure herbicides are applied during the correct growth stages.

Anyone who discovers a possible crop disease or has questions about field conditions can contact the Mercer County OSU Extension Office at 419-586-2179.