Studies on the mode of action of asulam in bracken (Pteridium aquilinumL. Kuhn)

Abstract

SynopsisThe efficiency of bracken control using foliage-applied translocated herbicides depends upon the accumulation of a potentially lethal concentration of the active ingredient at the sites of action, the rhizome buds. There is evidence that the level of herbicide accumulation at these target sites is determined by a number of factors including the efficiency of cuticle penetration, absorption, translocation, metabolism and activity at the enzyme target sites. The level of metabolic activity of the rhizome/frond buds may be critical, dormant buds possibly receiving a sublethal dose. These buds may later become active and act as foci for reinfestation.The nature of these problems is discussed with particular reference to studies carried out on the mode of action of [14C]asulam.