Glyphosate is the world’s most widely used herbicide, accounting for 11 % of worldwide herbicide sales (Powles et al., 1997). As a nonselective herbicide with no soil activity (Grossbard & Atkinson 1985), it is an ideal
herbicide to control a broad range of weed species. In Malaysia, glyphosate is used to control various weed species growing in oil palm and rubber plantations. In some instances, multiple treatments have been carried out
continuously for several years