Taken from Purdue Extension, Chat and Chew Cafe – September 11, 2020 – Issue 2020.24 – By Bob Nielson
Droopy ears are cute on certain breeds of dogs, but droopy ears on corn plants prior to physiological maturity are a signal that grain fill has slowed or halted. Ears of corn normally remain erect until some time after physiological maturity (black layer development) has occurred, after which the ear shanks eventually collapse and the ears decline or “droop” down. The normal declination of the ears AFTER maturity is desirable from the perspective of shedding rainfall prior to harvest and avoiding the re-wetting of the kernels. PREMATURE ear declination, however, results in premature black layer formation, lightweight grain, and ultimately lower grain yield per acre.
What Causes Premature Droopy Ears? The most common contributing factor is severe drought stress that extends late into the grain-filling period. I have seen droopy ears in quite a few fields around Indiana these past few weeks in areas afflicted with severe drought stress. Even though Indiana has not experienced a lot of excessively hot (≥ 95o F) days in 2020, drought conditions coupled with sunny days and unusually low humidity (i.e., low dew point temperatures) result in significant evapotranspiration demands on the crop during grain filling. In most of the affected fields, the severity of leaf rolling and premature leaf death (senescence) due to drought stress was also high. Continue reading