EVALUATION OF STANCE AS A PLANT GROWTH REGULATOR IN IRRIGATED COTTON IN THE TEXAS HIGH PLAINS

摘要

The objectives of this two-year (2004-2005) project were to document the effects of several mepiquat-based plant growth regulators (PGRs) on cotton growth and development, crop maturity, lint yield and fiber quality in the Texas High Plains. The trials were conducted at two locations each year, Muleshoe and Lubbock, TX. The Muleshoe site was conducted in a commercial sprinkler irrigated cotton field in both years and the Lubbock site was located in a commercial subsurface drip irrigated field in 2004and in a commercial sprinkler irrigated cotton field in 2005. The experimental design was a randomized complete block with four replications of treatments. Plots were 4 rows wide by 50 feet long. The plots were hand harvested and samples were taken fromeach plot to obtain percent lint turnout and fiber quality. Samples were ginned at the Texas A&M University Agricultural Research and Extension Center at Lubbock. Lint samples were submitted to the Texas Tech University International Textile Center at Lubbock for high volume instrument (HVI) analyses. Stance performed similarly to other PGRs (Mepichlor, Mepex, or Pentia) included in this two year study. Stance was effective in reducing plant height and in most cases height to node ratio, as were othermepiquat-based PGRs. In two of four trials, most PGR applications slightly enhanced maturity by reducing days from planting to physiological cutout. These replicated small plot trials conducted in the High Plains of Texas did not document any statistically significant yield responses to PGRs. There was also no significant fiber property response associated with the application of any PGRs.