Effects of alternative weed management strategies on Commelina diffusa Burm. infestations in Fairtrade banana (Musa spp.) in St. Vincent and the Grenadines

Alternatives to herbicides are needed for weed management in banana cultivated under the Fairtrade system in the Windward Islands. Field trials were conducted in established banana orchards under irrigated and non-irrigated regimes in the rainy and dry seasons, 2003–2004, to evaluate the effects of selected treatments on the weed composition response in fields previously infested with Commelina diffusa Burm. The treatments consisted of three leguminous live mulches (Desmodium heterocarpon (L.) DC., Mucuna pruriens Bak. and Arachis pintoi Krap. & Greg.), three non-living mulches (coffee hulls, banana mulch and clear plastic mulch), two herbicides (fomesafen and glufosinate-ammonium) and two organic treatments (corn gluten meal and concentrated vinegar and acetic acid). Treatments significantly shifted the species composition away from Commelina diffusa to annual weed species such as Spermacoce latifolia Aubl. and Cleome aculeate L. Banana mulch treatment provided the best control by significantly reducing weed biomass and weed species composition and was followed by Fomesafen, coffee hulls, clear plastic mulch and Desmodium heterocarpon. This study indicates further research to refine mulched based weed management systems is needed in banana orchards.