不同密度下封顶方式对南疆棉花生长及产量性状的影响

针对当前棉花生产过程中人工封顶耗时、低效、高成本的问题,探讨种植密度与封顶方式对棉花产量和纤维品质的互作效应,分析化学封顶代替人工封顶的可行性,无疑将对实现棉花的全程机械化、减少劳动量和降低种植成本具有重要的意义。化学封顶是棉花全程机械化简化栽培的技术内容之一,其对不同群体棉株生长及产量形成具有一定影响。以419为材料,开展裂区设计试验,密度为主区,设9万株/hm2、18万株/hm2和27万株/hm2三个水平;封顶方式为副区,设不封顶、人工封顶和化学封顶共3种方式,研究不同种植密度下棉花封顶方式的效应,分析化学封顶代替人工封顶的可行性。结果表明:在相同封顶方式下,随密度增加,生殖器官干重运转率和LAI有所增加,但单株叶面积、单株干物质积累和收获指数降低,株高则变化不大。在相同密度下,封顶方式对单株叶面积、LAI及单株干物质积累影响不大;封顶处理的株高较不封顶处理降低4.90～6.46 cm,生殖器官干重运转率、收获指数、衣分和产量分别提高6.33～9.47个百分点、0.03～0.05个百分点、0.03～1.01个百分点和529.56～301.42 kg/hm2。与人工封顶相比,虽然化学封顶的单株叶面积、LAI、株高和单株干重分别提高0.01 m2、0.11、1.56 cm、1.80 g/株,生殖器官干物质转运率、收获指数、衣分和产量分别降低3.14个百分点、0.03、0.42个百分点和228.14 kg/hm2,但各性状间差异不显著。各性状受密度与封顶方式互作的影响较小。以上说明封顶是优化棉花生长、保证产量的关键措施,而化学封顶具有类似人工封顶的效果。

Influences of Different Topping Methods on Cotton Growth and Yield Traits Under Different Plant Densities in Southern Xinjiang

In order to resolve the problems of of time-consuming, inefficient and high cost of artificial top-sealing in cotton production process, the interplay effect of planting density and capping on cotton yield and fiber quality was explored, and the feasibility of replacing the artificial seal with chemical seal was analyzed. As one of the techniques of mechanized and simplified cultivation of cotton, chemical topping has certain influence on the growth and yield formation of different populations of cotton. In this paper, 419 was used as the material for the split plot experiment. The density was the main area including 9×104 plants/hm2, 18×104 plants/hm2 and 27×104 plants/hm2; the topping mode was the sub-area including no-topping, artificial topping and chemical topping. The effects of different topping methods under different planting densities were studied, and the feasibility of chemical topping instead of artificial capping was also discussed. The results showed that: Under the same topping method, the translocation rate of reproductive organ dry weight and LAI increased with the increase of density, but the leaf area, dry matter accumulation and harvest index decreased, and the plant height changed little. Under the same density, topping method had little effect on leaf area per plant, LAI and dry matter accumulation per plant. Compared with the no-topping treatment, the plant height of topping treatment was reduced by 4.90～6.46 cm, and the dry matter translocation rate of reproductive organs, harvest index, lint content and yield were increased by 6.33～9.47 percentage points, 0.03～0.05 percentage points, 0.03～1.01 percentage points and 529.56～301.42 kg/hm2, respectively; Compared with artificial topping, though the leaf area, LAI, plant height and dry weight per plant of chemical topping treatment were increased by 0.01 m2, 0.11, 1.56 cm and 1.80 g/plant, respectively, the dry matter transport rate, harvest index, lint percentage and yield were decreased by 3.14 percentage points, 0.03, 0.42 percentage points and 228.14 kg/hm2, respectively; but there was no significant difference among the characters. The interaction between density and topping method is less affected. The above showed that topping was the key measure to optimize cotton growth and ensure yield, and chemical topping had the similar effect of artificial topping.