The month of May has given local farmers wet, soggy and cool soils with the result being fields with uneven stands of corn and soybeans. Cool, wet soils slow the germination and emergence of plants, which leads to increased seed rots, seedling blights, occurrences of insect damage, nutrient deficiency and herbicide injury.
As I check fields, it is not uncommon for me to see corn plants that are in the five-leaf stage (V5) while another plant is only at the two- or three-leaf stage. In addition, numerous fields have areas where water stood for days, which resulted in either no plants surviving or a scattering of plants. Where farmers have been able to replant the ponded areas, these spots are just emerging or they have been re-flooded by another heavy rainfall event.
For the month of May, our growing degree-days have fallen behind normal. This adds to the problems of our local crops with slower crop growth and slower recovery from herbicide and insect injury. All of these plant problems are predisposing these same crops to increased risk to future disease and insect problems.
These early seedling blights may show up later this season in corn as Pythium or Fusarium infections in stems or roots. Crazy-top and Physoderma brown spot are likely in areas where corn plants were under water. In soybeans, the disease of Pythium, Fusarium and Phytophthora may show up later in the growing season as areas of dead or weak plants. In addition, insects are attracted to weakened plants.This year, monitoring your fields on a regular basis will probably pay big dividends. Remember catching a crop problem early can make the difference between success and failure, profit or lose.