东南亚国家如越南、泰国、菲律宾、马来西亚等国，近年来水稻栽培方式迅速从插秧改为直播，因而杂草种类及群落也随之发生变化，即禾本科杂草危害加重。杂草防治除选种、平地、水层管理等农业措施外，主要采取化学药剂防治。70年代开始使用敌稗，80年代逐步推广高活性除草剂，? Southeast Asian countries such as Vietnam, Thailand, the Philippines, Malaysia and other countries, in recent years, rice cultivation methods from planting transplants quickly changed to direct seeding, so weeds species and community also will change, that grass weeds more harmful. Weed control In addition to selection, leveling, water management and other agricultural measures, the main chemical control. In the 1970s, propanil was used. In the 1980s, highly active herbicides were gradually promoted.