Study On The Herbicide Formula Of Water Seeded Rice Fislds And Preparation Of The 54% Benthiocarb·Pyridine-Ethyl Oil Flowable Concentrate

This study selected E. crugalli,L. chinensis,E. prostrata and C. difformis for research, and tested activity of herbicides to these 4 weeds in the greenhouse condition. Greenhouse experiments showed that Benthiocarb had the highest inhibition to E.crugalli and L. chinensis, Pyridine-ethyl had the highest inhibition to E. prostrata and C. difformis. We got the optimum proportion of these 2 herbicides; and defined the formula composition and processing of the oil flowable concentrate; control technology of weeds in the water seeded rice fields was made clearly by field experiments. Results obtained are listed as following:Activity experiments showed that Benthiocarb had high inhibition to E. crugalli and L. chinensis, whose inhibition of plant and fresh content to E. crugalli reached to 85.24% and 88.15% each other by soil treatment; inhibition of fresh content to E.crugalli and L. chinensis reached to 91.24% and 82.56% each other by leaf treatment; Pyridine-ethyl and Bensulfuron were highly inhibit to both E. prostrata and C. difformis, whose inhibition of fresh content were both over 91%, and the activity of Pyridine-ethyl was higher than Bensulfuron. Above all, we selected Benthiocarb and Pyridine-ethyl to complex for next experiments.Data analysised by Gowing method showed that mixed formulations could control gramineae,broad-leaved grass and cyperaceae weeds, and the joint effect was addition. The optimum proportion of Benthiocarb to Pyridine-ethyl was 55 to 0.8-1. According to the principles of expanding kill-weeding table, reducing the costs and increasing the effects, we difined the proportion of the two herbicides was 53.1 to 0.9, and total active ingredient of preparation was 54%.Benthiocarb was easy to break down when meet water, so it was appropriate to be made into oil flowable concentrate, whose advantages included environmental friendly,high efficacy and so on. So we decided to develop the 54% Benthiocarb·Pyridine-ethyl oil flowable concentrate. Through the selection of propineb of the 54% Benthiocarb·Pyridine-ethyl OF, the optimum formulation were as follows:total active ingredient was 54%, ABSCa was 4%, alkylphenol ethoxylate was 6%, silica was 4%, defoamer was 0.2%, and oil was 31.8%. Ball mill worked at 500rpm for 3 hours, and all indexs confonned to the requirements for the formulation.Field trials showed that 54% Benthiocarb·Pyridine-ethyl OF was significantly improve the control effect by either soil treatment or leaf treatment, and the control effect of soil treatment was better than leaf treatment, so soil treatment was recommended. It was required 1 to 2 centimeter water layer for 4 to 5 days.54% Benthiocarb·Pyridine-ethyl OF could simultaneously control E.crugalli, L. chinensis, broad-leaved grass and cyperaceae weeds at 80 ga.i./667m2 at the recommended dose. It was security to use 54% Benthiocarb·Pyridine-ethyl OF at 60 to 160 ga.i./667m, which had no negative effect to tillering,height and weight of rice.