Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/5/2010
Publication Date: 9/8/2010
Citation: Pettigrew, W.T. 2010. Impact of varying planting dates and irrigation regimes on cotton growth and lint yield production. Agronomy Journal. 102:1379-1387. Interpretive Summary: Previously we’ve demonstrated that fairly consistent yield improvements can be achieved from planting cotton during the first week of April rather than the more traditional planting window of the first week of May. Early planted cotton partially achieves these yield improvements because its peak blooming period has been shifted closer to the longest day of the year (summer solstice) allowing the early planted cotton set the majority of its crop prior to the historically hottest and driest part of the year (late July and August). Because all the prior planting date research were performed under irrigated conditions, the current research evaluated the planting date response under both irrigated and dryland conditions to determine if similar yield improvements from early planting would be achieved under dryland conditions as they were with irrigated conditions. During this 4 year study, irrigation increased lint yields during 3 of the 4 years. During 2 of the 4 years, early planting increased lint yield by 13% but it never increase lint yield under dryland conditions. Early planting actually decreased lint yield under dryland conditions for 1 of the 4 years, but not under irrigated conditions that year. During the 4 years of this study, early planting clearly needed irrigation to achieve its yield benefits. This attribute implies that dryland producers should not adopt an early planting strategy. The results from this research will be used by cotton researchers, extension specialists, consultants and producers as an unbiased source of information to aid in making cotton production decisions.
Technical Abstract: Yield enhancements can be obtained in the Mississippi Delta by planting irrigated cotton (Gossypium hirsutum L.) during the first week of April rather than the first week of May. Because it avoids some late season drought stress, early planting might also work for dryland production. Objectives were to compare the performance of early and normal planted cotton while grown under both irrigated and dryland conditions. Six cotton varieties were planted in the field at Stoneville, MS during either the first week of April (Early) or the first week of May (Normal) in 2005 to 2008. Half the plots were irrigated and half were dryland. Dry matter partitioning, light interception, flowering, lint yield, yield components, and fiber quality data were collected. With the exception of the hurricane plagued season of 2005, irrigation always increased lint yield regardless of planting date. In 2006 and 2007, early planting increased lint yield by 13% under irrigated conditions but not dryland conditions. Early planting decreased dryland lint yield by 35% in 2008 but not under irrigated conditions. Fiber from normal planted cotton was 5% stronger than from those early planted. Both early planting and dryland conditions had a propensity to increase the short fiber content. Based upon the four years of this research, early planting appears to need irrigation to achieve its yield benefits, which implies that dryland Mississippi Delta cotton producers should not adopt an early planting production strategy.