Effect of Cutting off the Upper Three Leaves during Early Heading Stage to the Yield Structure of Rice

Different rice varieties were used to study the effect of removing one of the upper three leaves or their combination on panicle number,seeds per panicle,grain weight,grain weight per plant.The results showed that the effects of different treatments on all the trait were flag+2nd leaf+3rd leaf flag 2nd leaf 3rd leaf.For most of the varieties,the sum effect value of cutting off three functional leaves individually was higher than the effect value of cutting off three functional leaves at the same time;while that of a few other varieties was apposite.Comparing with previous experimental results,it was found that when cutting off functional leaves under low density conditions,the percentage reduction of grain weight per plant could reflect the effect of the functional leaves on photosynthetic products better than the percentage reduction of ear weight.