水稻对稻瘿蚊为害补偿力与经济阈值研究

１９９４－１９９８年针对水地稻瘿蚊为害补偿力及经济阈值进行了研究，结果表明：⑴水稻对稻瘿蚊为害具有较强的补偿能力，但基本属于不足补偿，不同标葱梯度其补偿力不同，每造成１％的标葱引起的产量损失远小于１％，其补偿率一般在５５％－８０％之间，产量损失及其损失率与标葱数呈极显正相关，有效穗和产量补偿率与标葱数则呈显负相关；⑵在相同受害程度下，密植损失大，补偿力小，而稀植损失小，补偿能力大，秧苗期补偿效

The compensative ability and economic threshold of rice harmed by rice gall midge

In this paper, the compensative ability and economic threshold of rice harmed by rice gall midge (RGM)was studied during 1994-1998. The results showed that rice had strong compensative ability for harm of RGM. The rate of compensation of rice varied with the different number of leaffolder. Per unit of 1% leaflolder caused to less than 1% yield loss. In general, rates of compersation were usually in the range of 55%-80%. Yield loss and its rate were positively related to the number of leaffolder, but the number of panicle and yield compensation were negatively related with the number of leaffolder. At the same damage, yield loss in close planting was more than that in sparse planting, and the rate of compensation in close planting was lower than that in the sparse planting. Compensation effect of seedling stage was stronger than that of tillering stage. As the rice yield was 300kg, 400kg and 500kg per mu in Sanming city, the economic injury level was 6.49%, 4.87% and 3.89%, respectively. The economic threshold for harm of RGM was determined as 15%-20% leaffolder at tillering stage. As leaffolder rate of the 3rd RGM generation was 3%-4%, leaffolder rate of the 4th RGM generation could be up to threshold. The spray was suggested at the hatching peak of the 4th RGM generation.