Thursday, November 8, 2007 - 8:00 AM
335-1

Corn Grain Yield and Plant Characteristics in Two Water Environments.

Brian Frank1, Loyd Stone1, Alan Schlegel2, and M.B. Kirkham1. (1) Dep. of Agronomy, Kansas State University, 2004 Throckmorton Hall, Manhattan, KS 66506, (2) Southwest Research Extension Center, Kansas State University, Southwest Res. Ext. Center, 1474 State Highway 96, Tribune, KS 67879

Corn (Zea mays) yields are often reduced by limited pumping capacity of irrigation wells drawing from the High Plains aquifer. As a result of decreased well capacities in this region, many irrigation systems no longer have the ability to meet peak irrigation (water) needs during the growing season. The purpose of this study is to measure easily identifiable plant characteristics of corn genotypes and relate those characteristics with the ability to maintain yield under water-limited conditions. This study involved measuring various plant characteristics on 18 corn hybrids grown in irrigated and dryland conditions near Tribune, KS during the growing seasons of 2005 and 2006. For both years, hot and dry conditions occurred during silking which resulted in large differences and many poor yields in the dryland plots. The number of days to the initiation of silking was the variable most strongly correlated with variation in grain yield in the dryland environment. The number of days to the initiation of silking in the irrigated environment did not have a significant correlation with variation in grain yield. Other measurements including canopy temperature, PAR (photosynthetically active radiation), color, leaf angle, number of internodes, number of leaves, and leaf nitrogen had no significant correlation with variation in grain yield for both the dryland and irrigated environments in 2005 or 2006. By considering the number of days to the initiation of silking, a producer will potentially be able to better select a variety that will perform well in a growing season with potential or likely severe water cutbacks as a result of limited water supply or reduced well capacity.