Efficacy of Coco Peat Mulch treated with Aqueous Curry Leaves Extract on control Woody Borreria (Hedyotis verticillata (L.) Lam.) at the Vegetative Stage

Introduction of new weed management strategy for plantation in Malaysia is crucial since the present weed control methods are less effective and highly herbicide dependent, thus leading to development of herbicide resistance in weeds as well as environmental and human health concerns. The present study was undertaken to investigate the efficacy of coco peat mulch treated with aqueous curry leaves extract on control woody borreria (Hedyotis verticillata) under nursery condition. The bioassay weed species were treated with different application rate of coco peat mulch (4 t ha-1 and 8 t ha-1) and aqueous curry leaves extract (20% and 40%). There were 6 treatment application were used in this study. Coco peat mulch treated with aqueous curry leaves extract exhibited markedly variable herbicidal activites against the target weed species. The mean value (% of control) of the weed growth (except the root length) significantly inhibited with an increase of coco peat mulch rate and aqueous
curry leaves extract from 4 t ha-1 to 8 t ha-1 to 20% and 40% respectively. The weed emergence was strongly inhibited by 90% when the bioassay species were treated at 8 t ha-1
coco peat mulch + 40% aqueous curry leaves extract (T6). Similar trend of inhibition on shoot fresh weight and root length also was observed at this application rate. The shoot fresh weight and the root length of H. verticillata were reduced by 80-90% respectively. There was no significant inhibition on the weed emergence, shoot fresh weight and root length at application rate of 8 t ha-1 coco peat mulch + 20% aqueous curry leaves extract (T5). This result suggested that coco peat mulch and aqueous curry leaves extract have synergistic effect in suppressed the Hedyotis verticillata.