Stress During Grain Fill: A Harbinger of Stalk Health Problems
Bob Nielsen
Serious crop stress during the grain filling period of corn increases the risk of stalk rots and stalk lodging (breakage) prior to grain harvest. Among the more common serious stresses that can occur during grain fill are nitrogen deficiency, foliar diseases (e.g., gray leaf spot, northern corn leaf blight), defoliation by hail, excessively wet soils due to heavy rains, excessively dry soils due to drought, excessive heat, and lengthy periods of cloudy conditions.
What these crop stresses share in common is that they can significantly reduce photosynthesis and the resulting carbohydrates necessary for kernel development. During the grain filling period of corn, the developing kernels become a significant photosynthetic “sink” for the products of photosynthesis and respiration. Corn plants prioritize the movement of these photosynthates to the kernels, even at the expense of not maintaining the cellular health of the stalk, leaves, and roots. For the rest of the article, visit Pest & Crop Newsletter.