Evaluation of regional cotton trial environments based on cotton fiber micronaire selection by using GGE biplot analysis

Cotton fiber micronaire is an important fiber trait which is directly related to yarn quality. This element of quality is the main limiting factor in cotton fiber quality improvement in the Yangtze River Valley. The optimal arrangement of a regional trial scheme is based on representative trial location identification. This is critical in enhancing both micronaire selection efficiency and regional trial cost-savings. Biplot GGE analysis has been the most useful statistical and visual tool for trial location evaluation and representative location selection, and it has been extensively adopted in cultivar stability and trial location similarity analysis in several crops. So far, however, little has been done in terms of cotton regional trial location evaluation based on fiber micronaire selection. The objective of this study was to single out ideal trial locations in cotton micronaire selection using biplot GGE analysis. The method was applied to 27 independent sets of cotton variety regional trials in 15 trail locations in the Yangtze River Valley in 2000 2010. Based on the evaluation variables of desirability indexes for fiber micronaire selection, the order of the 15 trial locations was Jingzhou City > Huanggang City > Nantong City > Jiujiang City > Yueyang City > Shehong City > Changde City > Anqing City > Wuhan City > Nanyang City > Nanjing City > Cixi City > Xiangyang City > Jianyang City > Yancheng City. Jingzhou City of Hubei Province was the most ideal trial location, while Huanggang City of Hubei Province, Nantong City of Jiangsu Province and Jiujiang City of Jiangxi Province were the ideal trial locations. It implied that these locations were the most effective for eurytopic cotton cultivar selection and regional test points of optimal cultivar identification based on cotton fiber micronaire in the Yangtze River Valley. On the other hand, the cotton trial locations in Jiangsu and Zhejiang provincial coastal fields (Yancheng and Cixi) were not suitable for cotton fiber micronaire selection in the Yangtze River Valley. This article has fully demonstrated the efficiency of biplot GGE application in regional trial environment evaluation and therefore laid the theoretical basis for decision-making regarding fiber micronaire selection in regional/national cotton trials schemes in the Yangtze River Valley.