G80-526 The Effect of Weather on Corn: Preseason Precipitation and Yield of Unirrigationed Corn

This NebGuide examines the results of studies done on the effects of weather on unirrigationd corn. Studies of the effects of weather on unirrigationd corn in Nebraska between 1950 and 1974 show the following four factors to be closely related to yield: Technology--the availability of better hybrids, nitrogen fertilizer, herbicides, insecticides and other improvements have resulted in a yield increase averaging 1.3 bushel per acre per year since 1950. Preseason precipitation--that which occurred between September 1 and May 15 had a beneficial effect. Yield increased on the average of 1.1 bushel per acre for each inch that preseason precipitation was above normal. Temperature stress--this had a negative effect during ear formation, tasseling and grain filling stages. Yield decreased an average of 1 bushel per acre for every day between ear formation (12-leaf stage) and denting that temperature was 95°F or higher. Rainfall during grain fill--this had a positive effect. Yield increased an average of 1.5 bushel per acre for each inch of rainfall between tasseling and denting