Effects of Foliar Application of ARY-0469-001 on First-Position Boll Production Components of Flex and LibertyLink Cultivars: Boll Retention and Average Boll Mass

A study was conducted in 2008 to evaluate the effects of foliar applications of Chaperone on production characteristics of first-position bolls in transgenic cotton cultivars exhibiting Flex and Liberty Link technologies. The study was conducted at the Texas AgriLife Research and Extension Center in Corpus Christi. The cotton cultivars FiberMax 832LL and DP9063B2F were planted on March 15, 2005 to a plant population of 50,000 in 38’ row spacing. Due to lack of adequate rainfall, supplemental irrigation was applied during the growing season. Chaperone treatments consisted of mid-bloom foliar applications at two rates 5 oz/A and 10 oz/A at MB. The experimental layout included an untreated check and consisted of a randomized split-plot design with four replications, with cultivars as main plots and Chaperone treatments as sub plots.  At application time, 20 plants were tagged in all plots to mark the sympodium with the first-position bloom. After defoliation, first-positon bolls (whole bolls with burrs) produced by 10 consecutive sympodia in all 20 tagged plants were harvested and grouped by sympodium.  In untreated and treated plants these 10 harvested sympodia corresponded to 6 sympodia below the tag and four above the tag. This procedure allowed the comparison of first-position bolls of similar age across all treatments. Bolls grouped by sympodium were ginned after counting the number of bolls and measuring seedcotton mass. Data presented discusses the differential responses in boll retention and average boll mass along sympodia between the two transgenic cultivars to the two rates of foliar application of Chaperone.