You usually don’t see ears of corn outgrowing their husks, except in years with rather severe heat or drought stress during pollination. Bob Nielsen has received some reports of ears sticking out from husks this year.
The Purdue University Extension corn specialist can link some of the instances to drought or heat stress before tasseling, which was later relieved after pollination. However, some reports have come from areas that weren’t particularly stressed earlier in the season.
“We don’t have a good explanation for those cases,” Nielsen says. “We’ve typically seen it more in years like 2011, where there was drought in one portion of the state, or in 2012, where there was widespread heat and drought stress.”
Nielsen reported on the phenomenon in the Aug. 31 edition of the Purdue Pest and Crops Newsletter. Whether or not it’s an issue of concern likely depends upon how widespread the condition is within a field. If enough ear tips are exposed to bird damage and other pathogens, grain quality could be affected.
“We usually see it when there’s stress which stunts growth of the husks as they develop,” Nielsen explains. “Once the stress is relieved by rain or cooler weather, the cob portion often develops to normal length. If conditions are good for pollination and grain fill, you may get kernels out near the tip of the cob, extending beyond the husks.”
Stunting of husks is similar to stunting of the plant itself during stress, Nielsen says. What typically happens in this case, if stress was the cause, is that cobs grow once conditions correct themselves, but husks remain stunted.