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在田间试验条件下,以杂交棉兆丰1号为试验材料进行了不同膜下滴灌量的试验,探讨滴灌水量对南疆杂交棉群体光合性能、冠层结构及产量的影响。结果表明:限量滴灌条件下棉田土壤水分亏缺,群体光合速率(CAP)和叶面积指数(LAI)降低,群体呼吸速率(CR)及CR占群体总光合速率的比例(CRP)在盛花期上升,进入盛铃期以后又迅速下降,叶片平均叶簇倾斜角度(MFLA)增大,散射辐射透过系数(TCDP)和直射辐射透过系数(TCRP)增加,对光能的截获率降低。过量滴灌促进杂交棉生长势强的特性发挥,造成棉株营养体过旺,群体叶源量(CLSC)较高,但生育后期CR上升快,CAPP最低,光合物质累积量虽较高,分配到生殖器官中的同化物较少,产量下降。适量滴灌棉株长势稳健,叶片生理机能优化,CAP增强,LAI上升快,且后期能保持较高的LAI水平,较小MFLA,较低的TCDP和TCRP,群体对光的截获率高,产量较高。研究同时表明南疆地区兆丰1号的适宜滴灌定额为3 000~4 125 m3/hm2,产量可达7 714.3~8 289.5 kg/hm2,据此提出了杂交棉较理想的群体光合特征和冠层结构指标。
Under the field experiment, the experiment of drip irrigation under different film was carried out by using Zhaofeng No.1 hybrid cotton as test material to study the effects of drip irrigation on the photosynthesis, canopy structure and yield of southern cotton hybrid cotton. The results showed that under limited drip irrigation, soil water deficit, population photosynthetic rate (CAP) and leaf area index (LAI) decreased, and the population respiration rate (CR) and the ratio of CR to total photosynthetic rate , Then decreased rapidly after entering the rhizospheric period. The mean leaf cluster angle (MFLA) increased, the TCDP and the TCRP increased, and the interception rate of light energy decreased. Excessive drip irrigation promoted the growth vigor of hybrid cotton and resulted in over nutrition of cotton plant and higher CLSC, but CR increased rapidly at the later stage of growth, with the lowest CAPP and higher accumulation of photosynthetic substances Less assimilates in reproductive organs and lower yields. The proper amount of drip irrigation cotton plants grew steadily, the physiological functions of leaves were optimized, CAP was enhanced, LAI increased rapidly, and later LAI level was higher, smaller MFLA, lower TCDP and TCRP, population interception rate of light was higher, high. The results also showed that suitable drip irrigation quota of Meifeng 1 in southern Xinjiang was 3 000 ~ 4 125 m 3 / hm 2 and yield was 7 714.3 ~ 8 289.5 kg / hm 2. Based on this, the optimal photosynthetic characteristics and crown Layer structure index.