Utilizing Boll Production and Distribution to More Effectively Understand Performance of Cotton Varieties in Georgia

In 2008, over 86% of Georgia’s cotton acreage was planted to one variety, DP 555 BR.  In sharp contrast, the most popular variety planted in 2011 represented only 25% of the total crop, and it took nine of the most widely planted varieties to reach market share of DP 555 BR in 2008.  With this relatively large number of varieties and the frequent release of new varieties, there is a need to find more ways to evaluate variety performance.  One method that has been used to make comparisons among varieties involves analyzing boll distribution or the production of bolls with respect to main-stem node and sympodial fruiting position.  This study examined multiple varieties by conducting plant mapping immediately prior to harvest that documented total number of bolls produced, boll distribution, plant height, and total number of main-stem nodes in multiple irrigated and dryland locations during 2009, 2010, and 2011.  This information was used to help explain differences among varieties with respect to yield potential, variation in observed yield across environments, and response to plant growth regulators.