EFFECTS OF EARLY-SEASON WATER STRESSES ON CORN PRODUCTION

摘要

The corn vegetative stage is often considered the least sensitive stage to water stress and could provide the opportunity to limit irrigation water applications without severe yield reductions. The vegetative stage begins at crop emergence and ends attasseling when silks begin to emerge. Nine years of research was conducted at the Kansas State University Northwest Research-Extension Center in Colby, Kansas on a productive, deep, silt loam soil where irrigation was delayed in one-week increments, typically ranging from about June 10 to July 20. Delaying irrigation only statistically affected the yield components in three of the nine crop years. Overall, these results suggest that corn grown on this soil type has great ability to handle early-seasonwater stress, provided the water stress can be removed during later stages. In addition to the statistical results, graphical representations indicate that the pertinent yield components are related to measured July crop water use, available soil water,evaporative demand and to the ratio of well-watered evapotranspiration to the sum of irrigation and precipitation.