ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

The field experiment was carried out in three cotton growing seasons from 2011 to 2013. Cotton canopy normalized difference vegetation index (NDVI) was obtained by GreenSeeker at full bud stage, flowering stage, full boll stage, early wadding stage. Yields, from different nitrogen application rates, were collected at harvest stage and compared with each other. Canopy NDVI, changing with nitrogen application level and growth period, were analyzed, separately. Furthermore, the correlation analysis was done between yield and canopy NDVI. Yield estimation models were established for cotton based on NDVI value. Results indicate that, in the four growth stages, with N rates increasing, canopy NDVI value presents a trend of “l(fā)ow high low”. And the correlation coefficient between canopy NDVI and yield is 0.7137,，0.8479，0.8979,，0.6926, respectively, and significantly positive correlative at flowering stage(P=0.0034) as well as full boll stage (P=0.0008). Regression between predicted yield and measured yield values of the year of 2013 shows that the correlation coefficient is maximum at full boll stage (R2=0.9082), and the root mean square error(RMSE) is 301.67kg/hm2, while the relative error (5.15%) is minimum. The results suggest that it is especially feasible to use canopy NDVI to estimate yield of cotton at the full boll stage.