两种氮肥用量对超级稻产量性状和病虫害发生的影响

以6个超级杂交稻组合为材料,初步研究了两种氮肥用量条件下对水稻产量性状和病虫害发生的影响。结果表明,施纯氮360 kg/hm²与施纯氮180 kg/hm²相比,水稻单位面积的有效穗数增加,单株的每穗粒数、结实率和千粒重下降,1 hm²稻田减产6.2%～10.3%。氮肥施用量过高,造成水稻生育后期稻纵卷叶螟、褐飞虱、水稻纹枯病和烟煤病危害加重,尤其是易引起腐生性煤炱菌的滋长。

Effects of two nitrogen applications on yield components and occurrence of major diseases and insect pests of super hybrid rices

Effects of two nitrogen applications(360 kg/hm2 and 180 kg/hm2) on the yield components and the occurrence of major diseases and insect pests were studied by using six super hybrid rice varieties.The results showed that the effective panicles per hm2 increased,but the grain number per panicle,seed setting rate and 1 000-grain weight declined,with yields decreased by 6.2%-10.3%.The diseases and insect pests,such as rice leaffolders,brown planthopper, rice sheath blight,sooty mould,were aggravated during the reproductive stage of rice at higher nitrogen level(360 kg/hm2) compared to the normal nitrogen level(180 kg/hm2).Higher nitrogen application stimulated reproduction of sapraphytic Capnodium sp.compared with conventional application.