A Review and Prospect on Herbicide Adjuvants

The history, present status and future prospects of adjuvants application in herbicides were briefly reviewed. Adjuvants could be separated into two groups, activator adjuvants and utility adjuvants. The former directly enhances the efficacy of a herbicide, through increasement of herbicide absorption, spreading, cuticular penetration, rainfastness and retention enhancement, and photodegradation of the herbicide can also be decreased. And the utility adjuvants is utilized for improving application characteristics, behaviors and physical properties of herbicides and reducing or minimizing unwanted side effects on application.According to chemical structure and resource, adjuvants can be classified into three types: surfactants, oils and inorganic salts. Inorganic salts can increase herbicide efficacy by improving absorption and/or rendering inactive of calcium(Ca2+), magnesium(Mg2+), or iron(Fe3+) ions in spray solutions. Oils adjuvants include petroleum oil concentrates, vegetable oil concentrates and esterified vegetable oils.Biological resources, environmental friendly, low phytotoxicity, biodegradable and high efficacy adjuvants will be the goal of adjuvant development. Some novel adjuvants were also introduced in this article. A suggestion to the research and development of adjuvants in China was given by the authors.