The rate of drying of corn left in fields last fall has been slow but steady, according to Joel Ransom, North Dakota State University Extension Service agronomist for cereal crops.
Ransom has been measuring the moisture level of corn in two Cass County fields with different hybrids that have not been harvested.
"From the middle of December, when the first moisture samples were taken, to March 5, the corn has been losing just slightly more than 0.1% of moisture per day," Ransom says. "This rate has been fairly consistent throughout the measurement period. This may seem agonizingly slow for those who are anxious to harvest, but we are now seeing moisture levels that are a bit more manageable."
Though still too wet to store without additional drying, the earlier hybrid sampled started out at 29% moisture but is now at 17%. The later hybrid started out at 31% moisture but is now at 21%. With temperatures rising, the drydown rate will start to accelerate.
"Most of the corn I've been monitoring is standing nicely and there has been no noticeable ear drop," Ransom says. "This is good news for yield, but don't expect an increase in the dried test weight for corn that did not reach maturity last fall."
Mold growth on corn ears was very common last fall, so there is some concern that it might flare up again and cause even more damage because of the warmer temperatures.
"With the drier corn that is now in the field, it is likely that the risk of renewed mold growth will be minimal," Ransom says. "However, a prolonged rainy period before harvest could cause molds to become problematic again. Grain that has been affected by mold should be dried to a safe moisture level before putting it into storage. Once in the bin, grain that had some mold growth before harvest certainly will be more susceptible to further damage than sound grain."