Enhanced plant growth, development and fiber yield of Bt transgenic cotton by an integration of plastic mulching and seedling transplanting

Plastic mulching and seedling transplanting are widely adopted intensive planting systems for cotton production in China. Previous studies have demonstrated considerable yield increases by individual use of mulching or transplanting compared with conventional planting. In the present study, two experiments were conducted to test if an integration of transplanting and plastic mulching is more beneficial than individual use of transplanting for enhancing cotton production, in northern Shandong, Yellow River Valley of China from 2003 to 2005. In the first experiment in 2003 and 2004, a hybrid Bt cotton cultivar SCRC 15 was planted in a greenhouse-like hut in early April, and the raised seedlings were transplanted to mulched or non-mulched field plots in early May. Plant growth and development, yield and yield components, and earliness of cotton were evaluated. In the second experiment in 2004 and 2005, three hybrid and three non-hybrid Bt cotton cultivars were managed with the integrated system or with transplanting alone, and yields of each cultivar were examined. Results from the first experiment showed that plant growth and development, yield and yield components, and earliness of cotton were significantly enhanced by an integration of mulching and transplanting compared with individual use of transplanting in either 2003 or 2004. Lint yields and the number of bolls per unit ground area were increased by 17.4% and 14.6% in 2003, and 17.1% and 15.3% in 2004 with plastic mulching in comparison with non-mulching, respectively. Such enhancement was mainly attributed to significantly increased soil temperature during early season after transplanting. The size of soil blocks for seedling nursing had significant and non-significant enhancement on final lint yield in 2003 and 2004, respectively. In the second experiment, average lint yields of hybrid cotton were increased by 17.8% in 2003 and 16.9% in 2004, and those of non-hybrid cotton were 13.3% in 2003 and 13.5% in 2004 with mulching in comparison with non-mulching (individual use of transplanting). It was concluded that an integration of plastic mulching and seedling transplanting can be more effective than individual use of transplanting to enhance cotton production in northern Shandong and other heat-limited areas.