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United States Department of Agriculture

Agricultural Research Service

Title: Managing Late-Season Drought in Corn and Soybeans

Author
item Westgate, Mark

Submitted to: Crop Pest Management Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 20, 1996
Publication Date: N/A

Technical Abstract: Water is the primary limiting factor in corn and soybean production. Despite continued selection for improved drought tolerance, grain yield in these important crops remain highly vulnerable to dry conditions during floral development and early seed growth. In both crops, drought during flowering decreases seed number per unit area. In corn, low seed numbers result primarily from a delay in silk emergence relative to pollen shed and an increase in seed abortion. In soybeans, drought increases pod abortion. Sensitivity to drought decreases as the seeds mature. In both crops, drought during seed filling shortens the duration of seed filling. In corn, the shorter filling period is caused by premature water loss from the seed. In soybeans, it results from a decrease in maximum seed volume. Selecting corn hybrids with rapid ear growth, tolerance to high population densities, or which are prolific can improve performance under drought conditions. Currently, there are no such selection criteria for soybean. Managing both crops to conserve water prior to flowering by decreasing plant population and planting in wide (30 in) rows will improve yield stability across environments. Irrigating corn prior to silk emergence and soybeans during pod expansion will return the greatest yield per unit water applied.

Last Modified: 7/22/2014
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