Pre-emergence Herbicide for Controlling Weed in Various Sugarcane Genotypes Grown under Late Rainy Season

Weeds cause a decrease in sugarcane productivity, so the application of pre-emergence herbicides can be used as a solution to control weeds. This study aimed to identify the most effective pre-emergence herbicide for weed management across multiple sugarcane genotypes under late rainy season conditions.

Split-plot design was used in this study with three replications. Four weed management strategies were assigned as main plots and four sugarcane varieties were assigned as sub-plots. Weed data, including control efficacy, weed biomass, weed density and weed species, were collected at 15-day intervals from 15 to 120 DAA. Plant height and tiller number of sugarcane were measured at 30, 60, 90 and 120 DAA.

The most common weed was Cyperus rotundus L. (purple nutsedge), followed by Indigofera hirsuta (hairy indigo). Weed control efficiency in diuron and pendimethalin + imazapic treatments was intermediate between hand weeding and weedy (untreated control) with similar patterns observed in overall weed scores from 60 to 120 DAA. Both herbicides reduced weed density and weed biomass between 60 and 120 DAA, with pendimethalin + imazapic being more effective than diuron at 105 DAA. Sugarcane genotypes had no significant effect on weed control efficiency, density, or biomass throughout the experiment. However, pendimethalin + imazapic in KPS01-12 resulted in a higher tiller number at 90 DAA and greater plant height from 90 to 120 DAA. Thus, pendimethalin + imazapic effectively reduced weed presence and supported the growth of certain sugarcane varieties during the late rainy season.