Keeping the soil moist through timely irrigation can keep corn cool as the crop enters the dog days of summer, according to Mississippi Extension corn specialist Erick Larson.
High temperatures can potentially reduce corn productivity, Larson notes. However, if you can effectively irrigate or have sufficient soil moisture in the soil profile, corn can minimize harmful effects of excessive heat through transpiration, which essentially cools the plants.
Thus, continue to carefully monitor soil moisture when scheduling irrigation and also attempt to minimize water ponding and saturation in the lower end of irrigated fields — as either water deficit or saturation can restrict transpiration.
Although many producers worry about heat causing failure, Larson adds that it rarely occurs solely due to high temperatures. He points out that highly productive irrigated corn in the High Plains generally sustains much higher temperatures during pollination and grain fill than corn in the Mid-South.
Severe water deficit is more likely to cause pollination failure because it delays silk emergence, relative to pollen shed from tassels. Thus, these processes may not coincide, leading to barrenness. The Mid-South’s high night temperatures and humidity are unfavorable for crop productivity, but there is little or nothing we can do about them.