Herbicides screening for chemical control of monochoria, the invasive weed, (Monochoria vaginalis) in paddy rice.
Monochoria vaginalis is an invasive weed of paddy rice fields and now has infested tens of thousands of hectares of rice fields in north, three decades after being reported for the first time in Iran. Late emergence, fast growing under rice canopy, flood tolerance and completion of life cycle after rice harvesting, allows monochoria to survive and escape from the common weed management practices in paddy rice. The efficacy of some herbicides for chemical control of monochoria in pot and field conditions were investigated in Rice Research Institute of Iran in 2017. The results of pot experiment showed that early post application (2-3 leaf stage) of soil applied herbicides including flucetosulfuron, pyrazosulfuron, benzobicyclon, pyrazosulfuron + quinclorac, triafamone + ethoxysulfuron controlled monochoria effectively (≥ 90%). Other herbicides including ipfencarbazone, thiobencarb, pendimethalin, pretilachlor, oxadiargyl and pyrazosulfuron (WG 75%) with 55% reduction in monochoria biomass were not satisfactorily effective. In the field experiment, foliar application of 2, 4-D, dicamba + 2, 4-D, bispyribacsodium, pyribenzoxim and triafamone + ethoxysulfuron reduced monochoria biomass 90% While propanil with 23% control had a poor performance in controlling of his weed.