Herbicide Effects on Target and Nontarget Weeds of Rice Fields in China: A Rational Control Strategy

Widespread herbicide applications during the last 20 years have altered prevailing weed species in rice fields; many nitrogen-fixing cyanobacteria were not found even though they were not targets of the herbicides. Four types of herbicides exhibited different toxicity to algae, and the algae displayed different degree of sensitivity to herbicides. A novel theory of the order parameter of rice-weed ecological system may be utilized to establish a better herbicide application strategy based on control parameters lambda of the rice-weed system.