Investigation On Weeds Of Direct Seeded Rice And Screen Herbicides In Hunan Province

In recent years,direct seeded rice has developed rapidly in Hunan Province.In order to know the plant area of direct seeded rice in Hunan Province,the types of main weeds and herbicides application level,as well as screen suitable herbicides for direct seeded rice,communicating with Station of Plant Protection & Quarantine,All county-level distributors,township retailers,and farmers,and shared informations from Industry Data from 2017 to2019.At the same time,field efficacy test was carried in Changsha County,Huarong County,and Tianmen City to evaluate Rinskor’s control effect on weeds and their safety to rice.The main results are as follows:(1)The plant area of direct seeded rice has been increasing steadily,and direct seeded rice has become one of the main planting types in Hunan ProvinceIn 2018-2019,the plant area of rice direct seeded field in Hunan Province increased from 7.217 million mu in 2018 to 8.047 million mu in 2019,an increase of 830000 mu,or11.5%.The proportion of direct seeded rice field in total rice plant area increased from19.28% in 2018 to 20.64% in 2019,an increase of 1.36%.It shows that direct seeded rice has become the main way of rice planting in Hunan Province.(2)The main broadleaf weeds in the direct seeded field are Monochoria vaginalis,Sagittaria pygmaea,Ludwigia prostrata and Alternanthera philoxeroides.The level of herbicides is closely related to cultivation mode and managementIn 2019,it was found that Monochoria vaginalis,Sagittaria pygmaea,Ludwigia prostrata and Alternanthera philoxeroides were the main broadleaf weeds in the direct seeded rice.The herbicides such as dimethyltetrachloride,bensulfuron methyl and pyrsulfuron methyl,which are effective to broadleaf weeds and sedge,are sold more in relevant areas.The cost of herbicides in direct seeded field is significantly higher than that in transplanting field.The level of pesticides in paddy field is closely related to the cultivation mode and management level.(3)Rinskor · King and Rinskor · Dan can control weeds in direct seeded riceRinskor ·King 80～100ml/ mu,Rinskor·Dan 60～ 80ml/ Mu + Qian-jin 150ml/ mu,in direct seeded rice during four leaves one heart to a tillering stage spray treatment of stem and leaf,15 d after the plant control effect 94.4% ～97.9%,after 30 d fresh weight control effect80.9% ～ 94.8%,can be used as a direct seeded field herbicide.