By Jamie Martin
Corn growers are being encouraged to monitor the effects of warm nighttime temperatures as research continues to show their influence on crop performance and final yields.
While extreme daytime heat often attracts attention, experts say high overnight temperatures can be equally important. When nighttime temperatures remain above 70°F, corn plants may experience increased stress that limits their ability to build and maintain yield.
“Unlike photosynthesis – which only happens during the day – respiration keeps running all the time,” said Mark Jeschke, Pioneer agronomy manager. “It’s a temperature-dependent reaction, so the warmer it is, the faster it goes. When the nighttime temperature increases, the total expenditure of energy through respiration also increases, leaving less energy to contribute to grain fill.”
The greatest risk occurs during the period surrounding silking, a critical stage when kernel numbers are established. Stress at this time can reduce kernel set, ultimately lowering yield potential. Heat can also affect later stages of development by reducing kernel weight and weakening stalk quality.
One of the main reasons for yield loss is increased respiration. Unlike photosynthesis, which only takes place during daylight hours, respiration continues throughout the day and night. Warmer conditions cause plants to use more stored energy, leaving fewer resources available for grain production.
High nighttime temperatures can also speed up crop development. Faster growth often leads to earlier maturity, reducing the length of the grain fill period. With less time available for kernels to develop fully, overall yield can decline.
Additional impacts of prolonged heat may include greater water stress, accelerated leaf aging, reduced photosynthetic activity, and lower pollen quality. Together, these factors can place significant pressure on crop productivity.
Research findings suggest that not all corn hybrids respond the same way to warm nights. Some varieties demonstrate stronger resilience, while others are more vulnerable to yield reductions. This difference could become increasingly important as climate trends continue to bring warmer summer conditions.
Photo Credit: getty-images-alinamd
Categories: National