Harvest is off to a slow start across the state. High moisture grain, crop maturity, and ear rots and stalk rots are some of the topics ISU Extension and Outreach field agronomists have been focusing on. Read on for more about what’s happening in specific regions of the state.
Northwest Iowa
Corn coming in to the Iowa State University Grain Quality Lab from field trials in central, northeast, and southeast Iowa has been affected by a variety of ear rot fungi, and many individual ears display symptoms of multiple fungi.
Mycotoxins are poisonous trace organic residues of mold deterioration. Mycotoxins are not alive themselves, but instead are very potent compounds causing, at very low dosages (parts per million (ppm) or parts per billion (ppb)), a variety of human and animal health problems. Individual mycotoxins are produced by specific mold strains under more restrictive growth conditions than for the molds themselves.
As the 2016 growing season draws to a close, agronomists and farmers are reminded to scout for stalk and ear rots of corn.
Corn fields should be scouted for ear rot and associated mycotoxin contamination. Corn damaged by hail is at risk of ear rots, as is corn that has experienced hot, dry weather with occasional rain - conditions that favor Aspergillus and Fusarium ear rot development.
Being able to identify ear molds will help producers as they scout fields to determine if ear rot is prevalent. Fields with mold on more than 10 percent of the ears should be harvested first.
White, gray, pink and even salmon-colored molds on ears, and stalk rots are showing up in Iowa corn fields this fall, potentially producing mycotoxins and weakening stalks.
