EFFICACY OF SOME HERBICIDE TREATMENTS IN COFFEE PLANTATIONS IN CAMEROON

Five chemical weed control trials were carried out in Robusta and Arab ica coffee plantations in Cameroon. Five glyphosate formulations were tested : Roundup (360), Roundup (120), Armada, Folar and Ricochet. Gra moxone, Basta, Touchdown (480 and 174) and Fusilade were also tested. The treatments were applied with a knapsack sprayer. Doses of approxim ately 60 1 of liquid per hectare were used. The efficacy of the produc ts and their persistence were evaluated by observing the percentage mo rtality of the weed population (grasses and dicotyledons) and the perc entage recovery of regrowth for two to five months following the treat ment. For identical doses of active ingredient, the efficacy of all th e glyphosate-based herbicides was equivalent. The efficacy of Touchdow n 480 was equivalent to that of Roundup (360) for an identical dose of commercial product. Under these trial conditions Touchdown 174 and Fu silade were less effective. Gramoxone, a contact herbicide, showed sat isfactory efficacy when used at the beginning of the dry season or on vegetation mainly composed of dicotyledons. Basta, another contact her bicide, showed poor efficacy in the wet season in a field invaded by g rasses. It should be tested under the same conditions as Gramoxone.