Maize hybrid response to tillage under irrigated and dryland conditions

The popularity of reduced-tillage cropping systems has emphasized the need to determine if maize (Zea mays L.) developed under conventional tillage systems (moldboard plow, disk, and harrow) is readily adaptable to conservation production systems (greater than 30% residue cover after planting). Past research has indicated that crops grown under conservation production systems are subjected to cooler and wetter soil conditions than crops grown with conventional tillage practices. Information is needed to determine if a significant interaction exists between tillage and hybrid in maize. Field experiments were conducted in 1982 and 1983 near Lincoln, Nebraska, U.S.A., on an Abruptic Argiaquoll and in 1983 near Gothenburg, Nebraska, U.S.A., on a Typic Haplustoll under dryland and irrigated conditions, respectively, to evaluate the response of eight hybrids to several tillage practices. Tillage practices studied were moldboard plow, tandem disk, and no-tillage. Tillage practice had a significant effect on only plant emergence at Lincoln during 1983 and dry matter production at Lincoln in 1982 and Gothenburg in 1983. Hybrids differed in plant population at harvest, rate of phenological development, leaf area and dry matter production, and grain yield. A significant tillage x hybrid interaction was observed for dry-matter production at the tasseling stage at Lincoln during 1983; however, no significant interactions were observed for grain-yield among the hybrids and tillage systems investigated. Results indicate that for the adapted hybrids tested, relative grain-yield comparisons will be maintained with both conservation and conventional tillage practices