Study On The Application Of The WP Of50%Isoproturon, Butachlor And Bensulfuron

There are two emergence fastigiums of weed in the paddy field in Jiangsu provience. The main emergence fastigium of weed was observed10-15days after sowing. The weeds compete with crop plants for resources and cause huge economic losses. The weeds emergenced10-15days after sowing they have a strong competitive power with crop plants in paddy fields. The pre-emergence applied herbicides play an important role in the weed management strategies. We have studied for bioactivitys of isoproturon, butachlor and bensulfuron and the compositions of the three chemicals in different ratios, preparation combination, toxicology, crop safety and application technique.According to the principles of expanding kill-weeding table, reducing the costs and increasing the effects, we found that the weed could be controlled by spraying the mixture herbicide of isoproturon, butachlor and bensulfuron. The mass ratio of isoproturon, butachlor and bensulfuron by24:24:2was identifiey through pot-bioassay and field bioassay.Optimum proportion of50%isoproturon-butachlor bensulfuron WP is as follows: active ingredient50%; wetting agent8%; dispersing agent4%; filler complement.The quality control index of50%isoproturon butachlor bensulfuron WP were studied. The results indicated that active content=50%, pH values=6-8, water<1%, suspension rate>90%, the wetting time<60s, disintegration time<3min.According to the experimental results of acute oral toxicity, acute dermal toxicity, acute eye irritation, acute dermal irritation, and sensitization,50%isoproturon-butachlor bensulfuron WP belongs to the category of low toxicity. It was safe to the operator and user.The safety of different dose of the50%isoproturon-butachlor bensulfuron WP to rice in difference stages were studied on rices planted in pots. The results indicated that the mixture was safe to rice when applied with60-90g/667m2in the growth frow stage of needle leaf to the period of one leave. The indica rice was more sensitivity than japonica. The best time of applying50%isoproturon-butachlor bensulfuron WP was2-4days after sowing in the direct sowed rice field, and the recommended dose was40-60g/667m2and100-120g/667m2in the direct sowed rice fields and dry sowed rice fields, respectively.The best time of applying50%isoproturon-butachlor bensulfuron WP was1-6days after interplanted rice in wheat fields, and the recommended dose was100g/667m2.The best time of applying50%isoproturon-butachlor bensulfuron WP was4-6days after rice transplant with machinery, and the recommended dose was40-60g/667m2. Keep moisture could be improved the effects of herbicide to the weeds.The product had gotten the registration on direct sown rice field. It mainly used in Jiangsu, Zhejiang, Hunan, and other proviences, average used area0.4million mu per year.