Author
Burke, John |
Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/12/2013 Publication Date: N/A Citation: N/A Interpretive Summary: The influence of applied plant growth regulators (PGR) on growth, development and yield in cotton has been studied for over half a century. The class of PGR known as cytokinins has been reported to exhibit both positive and negative effects; however, a majority of the studies report no significant effects on cotton. The objective of this study was to evaluate the effects of a foliar application of a commercial formulation of cytokinin during the early stages of seedling development, rather then later in development like earlier studies. The treatment early in plant development exhibited increased hypocotyl diameters, increased lateral root proliferation, and a breaking of apical meristem dormancy within one-week of treatment. Yield increases of 13% and 8.7% were observed in two years of the study. This study showed that application of cytokinin to cotton early in development has the potential to increase yields and reduce water stress in cotton. Technical Abstract: The influence of applied plant growth regulators (PGR) on growth, development and yield in cotton (Gossypium hirsutum L. and Gossypium barbadense L.) has been studied for over half a century. A recent study suggested that cytokinin treatment of young cotton seedlings may enhance overall performance and yield, especially in water-limited environments (Journal of Cotton Science 15:1–9 (2011)). The objective of this study was to evaluate the effects of a foliar application of a commercial formulation of cytokinin (6-benzyladenine) during the early stages of seedling development on DPL444BR yields under water-deficit conditions. Field studies in 2005, 2006, 2007 and 2008 compared untreated controls with 6-benzyladenine treated seedlings at the cotyledon to two-leaf stage. Greenhouse studies determined that a range of concentrations up to 300 µmol/mol 6-benzyladenine enhanced rooting, hypocotyl thickness, and seedling growth at this developmental stage. Concentrations of 400 to 1000 µmol/mol resulted in stunting of the seedlings and phytotoxic lesions on the cotyledon surfaces at the higher concentrations. In the field, seedlings treated with 300 µmol/mol 6-benzyladenine within two-weeks after planting exhibited increased hypocotyl diameters, increased lateral root proliferation, and a breaking of apical meristem dormancy. Increased cotton yields were observed in 2005 and 2008 compared with untreated controls. No yield enhancement was seen in 2006 possibly because of the severity of the drought experienced. This study showed that application of 6-benzyladenine to cotton early in development has the potential to increase yields and reduce water stress in cotton. |