Author
TAPLEY, MATHEW - AUBURN UNIVERSITY | |
ORTIZ, BRENDA - AUBURN UNIVERSITY | |
VAN SANTEN, EDZARD - AUBURN UNIVERSITY | |
Balkcom, Kipling | |
MASK, PAUL - AUBURN UNIVERSITY | |
WEAVER, DAVID - AUBURN UNIVERSITY |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/6/2013 Publication Date: 3/1/2013 Citation: Tapley, M., Ortiz, B.V., Van Santen, E., Balkcom, K.S., Mask, P., Weaver, D.B. 2013. Location, seeding date, and variety interactions on winter wheat yield in Southeastern United States. Agronomy Journal. 105:509-518. Interpretive Summary: In the Southeast US, wheat (Triticum aestivum L.) is a crop grown during the winter when climate conditions are usually influenced by El Nino Southern Oscillation (ENSO). Therefore, an understanding of how management practices can be adjusted to reduce the impact of climate-related risks became important for winter wheat production. Scientists at Auburn University in cooperation with a scientist with USDA-ARS located at the National Soil Dynamics Laboratory studied the effect of planting date on grain yield and yield components of three winter wheat cultivars with different maturity levels. The study was conducted during 2009-2010, 2010-2011, and 2011-2012 at three sites that represented different wheat growing conditions in Alabama. Results showed that grain yield and yield components were reduced as planting date was delayed but the impact changed among years and locations within a given year. When the current recommended planting date was delayed four weeks, yield losses ranged from 13% (North Alabama, 2010-2011) to 53% (South Alabama, 2011-2012), but planting two weeks earlier resulted in yield increases up to 17%. For all cultivars, the impact of delayed planting on seed mass was minimal when cold and wet growing conditions were prevalent, however; cultivar differences increased under warm and dry growing conditions. Results from this study showed that the cultivar and planting date must be selected on a location basis and those can be adjusted by using a seasonal climate forecast. Technical Abstract: In the Southeast US, wheat (Triticum aestivum L.) is a crop grown during the winter when climate conditions are usually influenced by El Nino Southern Oscillation (ENSO). Therefore, an understanding of how management practices can be adjusted to reduce the impact of climate-related risks became important for winter wheat production. The objective of this study was to evaluate the effect of planting date on grain yield and yield components of three winter wheat cultivars with different maturity levels. The study was conducted during 2009-2010, 2010-2011, and 2011-2012 at three sites that represented different wheat growing conditions in Alabama. Wheat was planted in a randomized complete block design with a split-plot arrangement of treatments and five replications. Four planting dates at approximately 15 day intervals were assigned to main plots, and three cultivars with early (AGS 2060), medium (AGS 2035), and late maturity (Baldwin) were randomized within subplots. Results showed that grain yield and yield components were reduced as planting date was delayed but the impact changed among years and locations within a given year. When the current recommended planting date was delayed four weeks, yield losses ranged from 13% (North Alabama, 2010-2011) to 53% (South Alabama, 2011-2012), but planting two weeks earlier resulted in yield increases up to 17%. Among yield components, seed mass showed the highest correlation with yield and the number of grains per spike the least correlation. The medium maturing cultivar had the highest seed mass among years and also the lowest number of grains per spike. For all cultivars, the impact of delayed planting on seed mass was minimum when cold and wet growing conditions were prevalent, however; cultivar differences increased under warm and dry growing conditions. Results from this study showed that the cultivar and planting date must be selected on a location basis and those can be adjusted by using a seasonal climate forecast. |