氮素营养对短季棉干物质生产与分配及纤维品质的影响

Effects of nitrogen on fiber quality,dry matter production and distribution in short season cotton:

合理施氮可显著增强短季棉盛花前根系活力，促使棉株稳健生长，还可增加单株叶片数，扩大群体叶面积指数，促进棉叶增厚，从而显著提高始絮前群体净光合生产率，增加干物质生产和结实器官干物质积累比例，协调营养与生殖生长。施氮处理Ｎ２的短季棉吐絮期生殖器官中干物质积累极显著地高于高氮处理Ｎ３和Ｎ４，分别提高了１４．２０％和３７．８０％，这可为多结铃，增铃重提供充足养分，同时还有利于提高纤维比强度。

The field experiment results showed that nitrogen nutrition could significantly improve agronomic character in short season cotton.On the other hand,in the suitable N level treatment (N 2),the leaf number per plant,specific leaf weight and leaf area index were increased significantly,and the root vigor of cotton plant before the flowering peak stage was also significantly enhanced.In addition,it could significantly increase net photosynthetic products and dry matter production,and coordinate the vegetative and reproductive growth,thus,photosynthetic material accumulation in the fruiting organs was significantly promoted, i.e. the significant effect on dry matter distribution in reproductive organ was observed,with 14.20% and 37.80% increase of distribution ratio in N 2 treatment than that of N 3 and N 4 treatments,respectively.Meanwhile,the fiber strength was improved,and no significant effects of N nutrition on the other fiber qualities were observed.