Potential of the Mixture of Cocoa (Theobroma cacao L.) Pulp Water with Glyphosate in Controlling Weeds in Oil Palm Plantations

Abstract

Weeds are an important issue in oil palm cultivation, and weed control systems are an important factor in increasing oil palm growth and production. Mixing herbicides with natural ingredients will be an alternative technique in controlling a wide spectrum of weeds in oil palm plantations. This study aims to determine the best concentration of mixing cocoa pulp water with the herbicide glyphosate in weed control in oil palm plantations. This research used experimental method of randomized block factorial design pattern with 3 repetitions. Of the fermented (L1) and non-fermented cocoa pulp water with concentrations of 75 mL (K1), 150 mL (K2), and 300 mL (K3), each of which was added with 1 mL/L glyphosate (G1). The control was 2 mL glyphosate (G2), so that the present study had 8 treatments. Data were analyzed by analysis of variance (ANOVA), followed by Tukey’s post-hoc test with significant level of 95% to know the real difference between treatments. The results show that the combination of unfermented cocoa pulp water with glyphosate has a significant effect on weed death in oil palm plantations. The combination treatment of 150 mL of cocoa pulp water without fermentation with 1 mL of glyphosate (K2G1) has the highest potential to kill weeds up to 87.94% (34.41% higher than the 2 mL glyphosate treatment) at the 4th week after application. Mixing unfermented cocoa pulp water with glyphosate (lower than recommended concentration) is effective in controlling weeds in oil palm plantations.