With temperatures predicted to be 100°F and heat index over 100°F this week, the question of “what is this heat going to do to my corn?” is always on people’s minds.
When temperatures are consistently above 87F during corn growth stages VT (Tassel) through Maturity (R6), significant negative impacts on corn yield and development can occur. During tasseling and pollination, heat stress can reduce pollen viability and silk receptivity, leading to poor kernel set and lower ear fill.
As the crop progresses through grain fill stages (most of the SC Crop is here now), elevated temperatures increase respiration rates and shorten the grain-filling period, reducing kernel weight and overall yield potential. When we experience high nighttime temperatures, carbohydrate accumulation in the grain can be limited, causing further losses.
Corn farmers should be managing soil moisture through the use of irrigation, where available, to help offset some of these high heat-induced losses. Future management to help with mitigating heat losses could be things such as selecting heat-tolerant hybrids and managing the crop to maintain good plant health through timely pesticide (herbicide, insecticide, and fungicide) applications as well as timely fertilizer applications.
