Weed Occurrence And Control Technology Integration In Machine-transplanted Rice Field In Hilly Area

Use of herbicide is the main method to control weeds in rice field.Herbicide use has accounted for 35.7% of total pesticide use.But extensive use of herbicide,has become the biggest obstacle of the pesticide reduction efficiency.This study through the hilly region paddy weed species investigation and analysis,on the basis of dominance analysis,found that Monochoria vaginalis(Burm.f.)C.Presl,Leptochloa chinensis(L.)Nees,Echinochloa crusgalli var.mitis and Ammannia baccifera L.are the major local paddy weeds.The occurrence rules of the four kinds of weeds was studied and control optimum period was determined.Application technology of pretilachlor + bensulfuron-methyl in spray synchronous mode was cleared.And two kinds of additives for the handling of the herbicide by common stem leaf efficiency reduction effect were compared.Combined with the experimental results of different weed control mode,different weed control efficiency and the field management of time nodeare analyzed.The key technology withchemical weed control mode of "1 seal 1 block" as the core was intensified.Through the key technology and the integration of agricultural measures,physical measures,the hilly region machine paddy weeds comprehensive control pattern was innovated.The results showed that:1.Control objects and control optimum stageThere were 15 species of weeds belonging to 10 families in the machine-transplanted rice field,including 4 species of Gramineae,2 species of Cyperaceae,2 species of Lythaceae,1 species each in the family Ponderaceae,Brassicaceae,Primulaceae,Scrophulariaceae,Onagraceae,Alismataceae and Potamogetonaceae.The dominant species of weeds in gramineae were aquilaria sinensis,Leptochloa chinensis(L.)Nees and weedy rice.The dominant species of Barnyard grass were Monochoria vaginalis(Burm.f.)Presl,Ammanniabaccifera L.and sagittaria pygmaea.And the dominant species of cyperaceae was Heleocharis plantagineiformis Tang et Wang.The emergence peak of Barnyard grass was 3-10 days after rice transplanting,and the emergence peak of Leptochloa chinensis(L.)Nees was 3-14 days after rice transplanting.The emergence peak of Monochoria vaginalis(Burm.f.)Presl and Ammanniabaccifera L.were 7-25 days after rice transplanting.Barnyard grass and Leptochloa chinensis(L.)Nees was 5 leaf stage at 25 days after rice transplanting.The suitable time for spraying herbicide on stems and leaves was 7-25 days after transplanting.2.Prevention and treatment of drug and prevention modelThe control effects of Herbicides sprayed when fields rototilled on weeds ranged from high to low: Isoproturon·Pretilachlor·Halosulfuron-methyl,pretilachlor + bensulfuron-methyl,bensulfuron-methyl·mefenacet.The control effects of pretilachlor + bensulfuron-methyl on weeds ranged from high to low: be sprayed while rice seedlings transplanted,be spilted mixed fertilizer at 7 days after transplanting,be sprayed at 2 days before transplanting.The control effects of 3 kinds of herbicides by sprayed or driped while transplanting on weeds ranged from high to low: oxadiargyl·butachlor+ triafamone,oxadiazon·pretilachlor,pretilachlor + bensulfuron-methyl.The control effects of common Herbicides sprayed on leaf and stem on Gramineous weeds ranged from high to low: florpyrauxifen +cyhalofop-butyl,isoproturon·pretilachlor·halosulfuron-methyl,pyraclonil,propyrisulfuron+ cyhalofop-butyl,metamifop·cyhalofop-butyl,penoxsulam+ cyhalofop-butyl.The control effects of bentazone,MCPA-dimethylammonium,MCPA·bentazone on broadleaf weed was more than 90%.The addition of auxiliaries “gaozhan” or “jijian” could increase the control effect by 1% ～ 16%,when same amount of herbicide used.And The addition of auxiliaries could ensure that the effectiveness of prevention does not significantly decline when 20% reduction in herbicide use.3.Prevention and control technology to optimize the integration and innovationThe integrated weed control management in machine-transplanted rice field in hilly area was integrated with the technology of "1 seal and 1 kill" as the core and with the assistance of agricultural and physical measures.Through field experiment,well integrated optimization the hilly region machine paddy mainly weed control technology,key technology integration application,created on the application of the local rice herbicides "reduced efficiency" goal has a better role in promoting.