Applied Techniques Research Of Herbicide Pyraclonil In Rice Fields

The harmful effects of weeds in paddy field is one of the main factors that affecting rice yield.Currently,chemical weeding control represents the main weed control technology.In this study,we choose the protoporphyrinogen oxidase inhibitor herbicide pyraclonil as our research object,to explore the herbicidal activity of pyraclonil on the main paddy weeds and its safety to different rice varieties.The field experiment was conducted to demonstrate the control effects and safety of pyraclonil in mechanical tran-planting rice field,and to clarify the application technology of peazaprazole in rice field.The results are as follows:1.The herbicidal activity of pyraclonil and its safety on riceThe herbicidal activity and the safety of pyraclonil were determined through whole bioassay in greenhouse.After 3 days of pyraclonil treatment with active ingredients of 150?195 g/hm2 the weeds showed leaves dry,yellow,stiff seedlings and other toxicity symptoms,the effective response was significantly faster than the control herbicide penoxsulam,pyraclonil could use to control common paddy weeds Echinochloa crusgalli(L.)Beauv.,Monochoria vaginalis(Burm.F.)Kunth.,Ammannia arenaria H.B.K.,Monochoria korsakowii,Sagittaria trifolia and Cyperus difformis,when applicated at 0,1 or 2 leaf stage of weeds,respectively.The inhibition rates of pyraconil on the fresh weights of these weeds were over 92%.Pyraclonil also has good control effect on Echinochloa oryzicola at 0 and 1 leaf stages of the expression of pyraclonil 48.6?291.6 g ai/hm2,Yuzhenxiang(Indica rice)was more sensitive to the expression of Yuzhenxiang.The selectivity indices of pyraclonil,which applied pre-emergence,in rice[Nanjing 9108(Japonica rice),Kliangyou 10(Indica hybridrice)]and E.crusgalli(L.)Beauv were all greater than 4,which indicated that pyraclonil was safety to 9108 and Kliangyou 10;The selectivity index of pyraclonil was significantly higher than 4 that of the application of pyraclonil at 4 leaf stage or 6 leaf stage of transplanted rice in['Nanjing 9108','K Liangyou 10' and 'Yuzhenxiang']and E.crusgalli(L.)Beauv.,it is safe for rice.2.Field test the weed control effect and rice safety of pyraclonil in mechanical transplanted paddy fieldThe effects of 2%pyraclonil GR on the mechanical trans-planting paddy fields were verified.The results show:after 12 days transplanting in mechanical trans-planting paddy fields,After 45 days of 2%of the oxazoline GR 180?360 g ai/hm2 treatment,the control effects on the number of stem or plant and the fresh weights of weeds such as E.crusgalli(L.)Beauv.,L,chinensis(L.)Nees,E.prostrata L.,M.vaginalis(Burm.f.)Presl,A.arenaria H.B.K.,C.difformis L.were all over 91%,thus the effect of this treatment is better than the two conventional treatment,and it is safe to rice.After 10 days transplanting rice 2%pyraclonil GR 180 g ai/hm2 sowing treatment once a drug can be effective control machine rice paddy field barnyard grass weeds,E.crusgalli(L.)Beauv.,L.chinensis(L.)Nees,E.prostrata L.,M.vaginalis(Burm.f.)Presl,A.arenaria H.B.K.,C.difformis L.,it is safe for rice.3.The demonstration of pyraclonil in mechanized transplanting rice fieldsIn 2016,we choose Lianyungang Gan Yu,Yancheng Fangqiang Farm,Xinghua,Huaian,Yangzhou,Taizhou Red Flag Farm,Yangzhou jiangdu,Liuhe,Nanjing,Jintan,Changzhou,Nantong Rugao,Wuxi,Yixing,Zhangjiagang of 13 regions,which have serious weed harms on their machine-planting rice fields,as demonstrate plots.The results showed applied pyraclonil at dose of 2%GR is 180 g a.i./hm2 was safety to rice,its control effects on weeds such as L.chinensis(L.)Nees.,Echinochloa spp.,A.arenaria H.B.K.,M.vaginalis(Burm.F.)Presl.,C.difformis L.are over 90%,thus it has a broad application prospect in the mechanical transplanted paddy field.