| In order to meet the needs of pesticide safety,environmental protection and labor saving,through adopting effective fenoxaprop-p-ethyl(FNE)and Cyhalofop-butyl to develop 1%fenoxaprop-p-ethyl effervescent tablet and 10%Cyhalofop-butyl spreading oil,the two labour-saving application method will have its good marketing value.(1)Fenoxaprop-p-ethyl(FNE)is a selective post-emergence herbicide controlling annual grass weed in dicotyledonous crops,such as in soybean,peanut,rape and so on.And it is also used to prevent grasses in wheat fields.In recent years,the complex of fenoxaprop-p-ethyl has good effect in controlling weeds in paddy field.In this thesis,the formulation of 1%fenoxaprop-p-ethyl effervescent tablet and its quality testing methods were studied.Then the composition and proportion of various ingredients of 1%fenoxaprop-p-ethyl effervescent tablet was identified.The herbicidal activity and safety test of the optimized formula was determined by petri dishes.The biological activity of this formulation was determined by field trial.The results were as follow:Through the determination of disintegration time and suspension rate,the carrier,sticker and dispersant agent of effervescent tablets were screened.The formulation of 1%fenoxaprop-p-ethyl effervescent tablet was fenoxaprop-p-ethyl 1%,sodium dodecyl benzene sulfonate 2.5%,soluble starch 6.5%,citric acid 12%,naphthalene sulfonate 3%,sodium bicarbonate 12%and anhydrous sodium sulfate up to 100%.Through the research on quality analysis method of the formula,we can draw the conclusion its disintegration time is short and suspensibility is high.After heat storage at 54?for 14days,the chemical degradation was qualified(chemical degradation 3.2%<5%),this formula met the requirements of pesticide effervescent tablet.Through the bioassay in laboratory,it was found:the toxicity of 1%fenoxaprop-p-ethyl EB on echinochloa crusgalli is slightly higher than its water emulsion.For the safety evaluation,the effervescent tablet is safe for 2-4 leaf stage of rice at 23g/ha and 92g/ha dosage.From the field trial,it was found:after application at 26g/ha and 78g/ha dosage,our sample(1%fenoxaprop-p-ethyl EB)mixing tillering control effect is 80.56%to99.84%for 15 days and 78.50%to 95.54%for 30 days.After application 30 days at26g/ha and 78g/ha dosage,its fresh weight control is 72.76%to 92.97%on Echinochloa crusgalli and 79.58%to 83.96%on Leptochloa Beauv.The effective ingredients of the control sample and our sample were 39 g per hectare,which the control effect is same and the difference is not significant(P<0.05).The performance of control effect increases with its dose adding.The control rice leaves were yellow,and the plants were dwarf,which caused phytotoxicity to rice.Compared with control sample,our sample(1%fenoxaprop-p-ethyl EB)did not have phytotoxicity to rice.(2)Cyhalofop-butyl is the type of widely used aryloxyphenoxy propanoate(AOPP)herbicide which is highly safe to rice.It had a prominent control effect on Echinochloa crusgalli and Leptochloa chinensis in rice fields.In this paper,the preparation of 10%cyhalofop-butyl spreading oil(SO),quality detection method,field efficacy and distribution on paddy field were studied.In this paper,cyhalofop-butyl was used as the effective ingredient to develop SO.The suitable solvent system and the ratio of surfactant were determined.Its quality testing methods as well as weeds control and safety to rice were studied.The biological activity of this formulation was determined by field trial.The results are as follows:The solvents were screened by determining and observing the dissolution of Cyhalofop-butyl in different solvents.Then,the spreading speed and area of different surfactants were preliminarily screened.Finally,the orthogonal formula was used to determine the final formula.And the formula was as below:the formula solvent turpentine oil 44%,surfactant op-4 3%,op-10 1%,film-forming additive 6%.The other component was carrier,which was 36.0%of the formulation.The spreading speed of 10%Cyhalofop-butyl SO was 9.52 cm/s and spreading area was 3490.84 cm~2.The formulation had been stored at room temperature,or(54±2?)for 14 days without precipitate,crystallization or layer-separation.The decomposition rate was qualified(chemical degradation 1.2%<5%).Surface tension was 27.48 mN/m.From the field trial,it was found:After application at 75 g/ha to 180 g/ha dosage,our sample(10%cyhalofop-butyl SO)mixing tillering control effect is78.49%to 93.76%for 15 days and 78.54%to 93.19%for 30 days.After application 30 days at 52g/ha and78g/ha dosage,its fresh weight control is 74.39%to 90.68%on Echinochloa crusgalli and 81.97%to 95.98%on Leptochloa Beauv.The effective ingredients of the control sample and our sample were 90 g per hectare which the control effect is same and the difference is not significant(P<0.05).Our sample(10%cyhalofop-butyl SO)did not have phytotoxicity to rice and application method labour-saving comparing with the control sample. |
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