Effects of Nitrogen Application on Cotton Growth and Yield under Light Stress

The main purpose of this experiment was to research the effects of nitrogen application on the growth and development and biomass accumulation and yield of cotton under light stress,the test materials from Hybrid CRI47were designed by split plot,50%shading and CK assigned to the main plot,deputy plot was 320kg/hm2 of pure nitrogen,on the basis of nitrogen application N1,N2and N3were three levels.The results showed that the yield of shading lint were decreased by 35.61%,compared with CK and growth duration extended by 15-18d,nitrogen fertilizer formard N1and N3,the boll opening when nitrogen fertilizer forward N1occurred earlier for six and five days than that when normal dressing fertilizer N2respectively,and the growth period of cotton shortened;A moderate amount of nitrogen fertilizer forward N1increased the plant height,true leaf number and width of the fourth leaf from top effectively,promoted the accumulation of biomass of cotton under shading,lint yield was 2 534.56kg/hm2,increased by 18.90%and 29.01%compared with N2and N3.A moderate amount of nitrogen fertilizer forward could shorten the growth period of cotton,increase bolls number and boll weight significantly under light stress.