WEED-CONTROL IN PEJIBAYE HEART OF PALM PLANTATIONS IN HAWAII

Pejibaye (Bactris gasipaes Kunth, Palmae) is being evaluated for produ ction of fresh heart of palm in Hawaii. Precocity, yields, and weed co ntrol were evaluated in response to woven black polypropylene mat (con trol), oryzalin, oxyfluorfen, and paraquat. Control plots attained 100 % of plants harvested hy 26 months, followed by oxyfluorfen (97.5%), oryzalin (77.5%), and paraquat (60%). Estimated heart of palm yields ( 3731 plants/ha) were similar with oxyfluorfen 1.2 kg a.i./ha (707 kg . ha(-1)), polypropylene mat (612 kg . ha(-1)), oxyfluorfen 0.6 kg a.i. /ha (600 kg . ha(-1)), and oryzalin 4.5 kg a.i./ha (478 kg . ha(-1)). Based on precocity, yields, and weed control efficiency, the performan ce rating of these weed control treatments was mat approximate to oxyf luorfen > oryzalin > paraquat. Chemical names used: 4-(dipropylamino)- 3,5-dinitrobenzenesulfonamide (oryzalin); ro-1-(3-ethoxy-4-nitrophenox y)-4-(trifluoromethyl) (oxyfluorfen); 1,1'-dimethyl-4-4'-bibyridinium ion (paraquat).