不同密度下打顶方式对短季棉生长及产量的影响

Effects of Topping Methods on Growth and Yield of Short Season Cotton under Different Densities

试验采用裂区设计,主区设置每公顷密度4.5万株和9.0万株两个密度水平,副区设置不打顶、人工打顶和化学封顶3种方式,研究不同密度下打顶方式对棉花生长及产量的影响。结果表明:密度增大,棉花株高和单产增加,而单株干物质重、单株果枝数和单株铃数减少;不同打顶方式比较,高密度下单株有效铃数、单铃重和籽棉产量由大到小的顺序为:化学封顶>人工打顶>不打顶,差异达到显著水平,低密度下差异不显著。综合来看,每公顷密度9.0万株下化学封顶处理的产量最高,为4 143.19 kg/hm^2,说明化学封顶更适于棉花高密度种植。

The split zone design was used in the experiment.The density of the main area was set as 4.5 × 104 plants/hm^2 and 9 × 104 plants/hm^2,and three topping methods were set at sub area as no-topping,artificial topping and chemical topping to study the effects of different topping methods on cotton plant growth and yield under different densities.The results showed that plant height and yield per unit area increased with the increase of density,but dry weight per plant,number of fruit branches per plant and number of bolls per plant decreased.The order of effective boll number per plant,boll weight per plant and seed cotton yield under high density was chemical topping > artificial topping > no-topping,and the difference reached a significant level,while there was no significant difference under low density.In general,the yield of chemical topping treatment under the density of 9 × 104 plants/hm^2 was the highest,which was 4 143.19 kg/hm^2.It indicated that chemical topping was more suitable for high density cotton planting.