有机水稻病虫草防治技术与经济效益分析

通过农艺措施，稻鸭共作和植物源药剂对有机水稻的病虫草害进行防治研究。结果表明：1．0％石灰水浸种催芽使秧苗期的恶苗病发病率低于1．0％；养草灭草结合养鸭除草和深水控草，使杂草最少的地块除草用工时间仅为完全人工除草地块的9．3％；调整播期避害，使得银香18的枯鞘率只有2．60％，白穗率为0．13％，9964的枯鞘率为1．51％，白穗率为0．58％；打捞浮渣使纹枯病的发生率低于1．0％；稻鸭共作使稻纵卷叶螟成虫虫口数下降78．8％，幼虫虫口数下降78．6％，有效卵下降36．4％；0．36％苦参碱水剂(百草1号)对稻飞虱的防治效果为71．2％，Bt制剂(青虫灵)对螟虫的防治效果不明显。尽管有机水稻的平均产量较常规生产降低了10．4％，投入成本提高了109％，但由于有机大米的价格是常规的2．78倍，因此有机水稻生产的经济效益更高。

Studies on organic rice pest,disease and weeds control techniques and analysis of their economic benefits

Proper agronomic practices,duck raising in the paddy field and application of phyto pesticides prove to be effective in controlling pest,disease and weeds in the production of organic rice.Soaking seeds in 1 0% lime water to stimulate germination reduced the incidence of bakanae disease down below 1 0% at the seedling stage.Growing and killing weeds in combination with duck raising and maintenance of deep water for weed control mitigated the labor time in weeding down to 9 3% as against the control.Proper seeding date,either postponing or advancing seed sowing,decreased the incidence of sheath withering down to 2 60% and of white spike to 0 13% with the cultivar of Yinxiang 18,1 51% and 0 58%,respectively,with the cultivar of 9964.The practice of removing foam from the paddy cut the incidence of stripe disease down below 1 0%.Duck raising in the paddy eliminated the population of the adult leafrollers by 78 8%,that of larvae by 78 6% and the number of live eggs by 36 4%,and spraying of matrine solution(Baicao No 1)controlled rice leaf hoppers by 71 2%,far too higher than Bt preparation(Qingchongling),which was not effective.Although organic rice is 10 4% lower in average yield and costs 109% more than the conventional one,it enjoys a sales price 2 78 times as high as the conventional one does.This brings about higher economic benefit for organic rice.