Proceedings 2004

Indiana Crop Adviser Conference

Back to Table of Contents

Drought Stress

Drought-Stressed Kernel Secrets: For Your Ears Only

The size, placement, and amount of kernel set on the corn ear documents when this ear was subjected to environmental stress and the severity of this stress. Four critical periods of ear growth and development are substantially influenced by environmental stress. In general, ear responses at these specific times include: „1 A reduction in the number of kernel rows around the ear if substantial stress occurs at or just before ear initiation (approximately V7). „2 A reduction in the number of kernels along the length of the ear or a shorter ear if substantial environmental stress occurs from the late vegetative phase until just before pollination. „3 A portion of the cob that may be completely barren if substantial environmental stress occurs during pollination. „4 A portion of the cob that shows either very small kernels or kernel die-back if substantial environmental stress occurs during grain fill. Understanding how corn ears respond to stress can help determine what stress was present, when this stress occurred, and how to mitigate this stress in the future.

Stephen Strachan Pioneer Hi-Bred

Biography:  Steve Strachan grew up on a corn and soybean farm in Illinois. He received his B.S. degree with a major in chemistry and a minor in agronomy from Western Illinois University in 1976. Steve then obtained an M.S. degree in Soil Biochemistry from Purdue University in 1979 and a Ph. D. degree in Plant Physiology from Purdue University in 1982. Steve joined DuPont Crop Protection as a Research Scientist where he worked as a member of the herbicide discovery team for new corn and soybean herbicides from 1982 to 1990. This research work included discovering new herbicide products, patent support, and monitoring degradation of herbicides in soil. In 1990, Steve moved to Iowa to serve as a technical development representative for new DuPont crop protection products. This work included field development of new herbicides and insecticides for corn and soybeans, assisting in writing new product labels, and technical support for the DuPont sales team working with corn and soybean farmers. In 1997, Steve joined Optimum Quality Grains as a corn production research agronomist. He then joined Pioneer in 2001 as a Research Scientist for the Parent Test group, where he is currently employed. Steve is responsible for determining the parental capabilities of new corn inbred lines and assisting Pioneer production teams in maximizing seed yield.