棉花花铃期以持续受渍为特征的排水控制指标试验研究

以地下水动态指标 SEWX 反映作物的受渍程度 ,利用田间小区试验研究了棉花花铃期持续受渍对产量与品质的影响。结果表明 :随着受渍程度加重 ,蕾铃脱落率上升 ,产量明显下降 ,此外 ,品质也受到一定影响。统计分析表明 :作物相对产量 RY与 SEW30 和 SEW50 之间有极显著的线性负相关关系 ,RY与 SEW50 之间的拟合优于 RY 与 SEW30 之间的拟合。考虑到持续受渍对作物产量的影响远比品质大 ,建议以产量作为作物排水指标选择的依据。如果以减产 1 0 %～ 1 5 %作为棉花排水控制指标选择的标准 ,则棉花花铃期的排渍控制指标 SEW30 应取 80～ 1 2 0 (cm· d)。

Study on the Suitable Drainage Indexes in Blossoming and Boll-forming Stage in Cotton

SEW x was used as an index of subsurface waterlogging in cotton and a field experiment was conducted to determine the suitable drainage indexes in blossoming and boll forming stage. Results showed that bud and boll drop rate increased significantly, yield was reduced distinctly, and fiber quality was degradedas well, with subsurface waterlogging development. Statistic analysis results showed that there was a significant negative linear correlation between relative yield R y and SEW 30 , and between R y and SEW 50 as well. The correlative coefficient between R y and SEW 30 was larger than that between R y and SEW 50 . Because the effect of continuous subsurface waterlogging upon yield was more obvious than that upon fiber quality, it was suggested that yield should be as a basis for determining drainage indexes. The suitable SEW 30 for drainage should be 80～120 (cm·d) in blossoming and boll forming stage in cotton, if 10%～15% of yield reduction was set as an assessing index.