水莎草+矮慈姑杂草组合对水稻产量的损失

Rice Yield Loss Caused by Weed Combination Juncellus serotinus+Sagittaria pygmaea

水莎草 +矮慈姑是稻田常见的杂草组合 ,对水稻生长有较大的危害。就这两种杂草不同密度的组合对水稻产量损失率进行测定、分析。结果表明 ,水莎草对水稻产量的影响极大 ,两种杂草组合对水稻产量损失影响更大 ,主要引起水稻有效穗数减少和每穗实粒数下降 ,导致减产 ;而千粒重对产量损失效应较小。水莎草与矮慈姑两种杂草间也存在生态竞争关系。

Juncellus serotinus (Rottb.)and Sagittaria pygmaea Miq.are very common co-existence weeds in rice field and can cause great damage to rice grwoth.Rice yield loss rates caused by the combination with different densities were measured and analyzed through field experiment.Fourty plants of Juncellus serotinus+ten plants of Sagittaria pygmaea made the most serious yield loss with the rate of 55.0% compared to CK (without these two weeds in rice field).The weed combination reduced rice yield mainly through decreasing the effective panicle no.,grain no.per panicle and 1 000-grain weight,and effect of the last one was small.Competition on growth between Juncellus serotinus and Sagittaria pygmaea was evident.