拜田净防除稻田杂草应用技术研究

试验结果表明,新型除草剂拜田净对移栽稻田和直播稻田杂草均具有良好的防除效果,以１００～１５０ｇａ．ｉ／ｈｍ＾２的用量在稗草１．５～２．５叶期施药,除草效果稳定在８９．６％以上,持效期为４０ｄ,与扫弗特和绕地奥相当,且优于二氯喹啉酸。拜田净的杀草谱包括稗草、千金子、异型莎草、陌上菜、鸭舌草,防效随剂量提高而增加,并且１．５叶期施药的除草效果比２．５叶期施药的好。拜田净以喷雾法和毒土法施用均较好的防效。直播稻田喷雾时要求田间土表湿润,药后１ｄ灌入薄水层;移栽稻田毒土撒施时要求田面保持水层３ｃｍ,药后保水５～７ｄ。同时,拜田净对水稻安全,但高剂量（２００～２５０ｇａ．ｉ／ｈｍ＾２）下对１．５叶期直播稻有一定的药害。

Application technipues of fentrazamide for the control of weeds in paddy fields

Trials showed that fentrazamide is highly effective on weeds in seedling-transplanted and direct seeded rice fields. Control efficacy of more than 89.6% and persistence of 40 d were obtained when fentrazamide was applied at a dosage of 100～150 g a.i./hm2 during 1.5～2.5 leaf-stage of barnyardgrass. The effect of fentrazmide on the weeds is similar to Sofit(pretilachlor + renclorim) and Lodeo (butachlor) ,and much better than quinclorac. The weeds that are controlled include Echinochloa crusgalli , Leptochloa chinensis , Cyperus difformis , Lindernia procumbens,Monochoria vaginalis. Control efficacy of the herbicide is better when applied in 1.5 leafstage of barnyardgrasa than in 2.5 leaf-satge,and increases with the raise of fentrazamide dosage,but no difference between spraying and broadcasting with soil. Besides,fentrazamide is safe to rice,while used at the dosage of 200～250 g a.i./hm2 it has a little phytotoxicity to direct seeded rice at 1.5 leaf.