Adjuvants and glyphosate activity

Additives can be used to enhance the biological performance of glyphosate, as well to improve the physical characteristics of its prediluted formulati ons. Their effects on efficacy can be mapped through a series of consecutiv e processes that the herbicide has to follow from spray tank to ultimate bi ological site of action. Key factors affecting dose transfer are discussed, including retention on foliage in the glasshouse and field, the effects of adjuvants on foliar uptake and the relationship between potential adjuvant effects and glyphosate concentration. A better understanding of the relati ve importance of the main barriers to glyphosate activity and the ability o f adjuvants to overcome them should enable a more rational approach to the design of glyphosate formulations in the future. (C) 2000 Society of Chemic al Industry.