Screening Of Herbicides And Synergistic Adjvants For Broad-leaved Weeds Control In Paddy Field

Weed is one of the main harm in in paddy field,especially the broadleaf weeds Sagittaria trifolia Linn.and Monochoria korsakowii Regel et Maack.,which cause increasing serious yield losses.Rice is one of main food crops in China.Therefore,the reasonable control of weeds in paddy fields is of great significance for ensuring the normal production of rice and safeguarding the interests of farmers.In this thesis,taking the weeds of rice fieldsas the research object,the chemical control techniquewas studied,and the combination of high-efficiency chemicals were screened,which could provide the basis for scientific,reasonable and sustainable weed control in paddy fields.Halauxifen-methyl is a novel herbicide for controlling broadleaf weeds in paddy fields.In order tokeep an optimal applicable effect,field experiments were designed and carried out to study the control effect and the best dose for halauxifen-methyl.Chemical control has been one of the main controlling measures against weeds in paddy fields for many years.However,the limitation of efficient pesticide varieties and unreasonable application of pesticides causes the rapid development of herbicide resistance.Faced with this,the mixture of different herbicides is used to increase control effect and delay the development of herbicide resistance.The combination of fluroxypyr and bentazone(4 : 1)as well as MCPA sodium,fluroxypyr and penoxsulam(8 : 9 : 5)has an excellent control effect on Sagittaria trifolia Linn.and Monochoria korsakowii Regel et Maack.in paddy fields.With the development of the country and society,requirement foragriculture is also increasing.It is the national requirementsto reasonable using of pesticides and to reduce the amount of applied pesticides.Penoxsulam exhibited excellent control effect against Sagittaria trifolia Linn.and Monochoria korsakowii Regel et Maack.in paddy fields.On this basis,enhanced-effect of the tank mixed adjuvant on penoxsulam was studied.The field tests confirmed that the tank mixed adjuvant could increase the control effect of penoxsulam.Mixed with this adjuvant,it is possible to reduce the amount of applied pesticides,which has economic significance for agricultural production and ecological significance for the environment.By farmers to control rice field weed survey found that cost and output auxiliary GY-T1602 for maintaining test reagent 480 g/L cut grass,200 g/L CFC pyrazole oxygen ethanoicacid(4:1)composite 796 g a.i./ hm2 and test reagents MCPA pyrazole oxygen ethanoic acid,sodium chloride,fluorine,five fluoride sulfonic grass amine(8:9:5)combination 440 g a.i./hm2 on paddy broadleaf weed control effect at the same time,can reduce the test reagent dosage,reduce the cost,increase crop yield,is effective fertilizer,chemical pesticide control technology is worth promoting.The application method was to spray the stems and leaves of rice once 7 days after transplanting,and apply 450 kg of liquid solution per hectare.