Control of Costus speciosus Sm in IOI Sabah oil palm plantations

摘要

Selective chemical weeding to control Costus speciosus, commonly known as white costus, a tropical weed is described. Potassium was the nutrient most immobilised in C. speciosus, and that was followed by nitrogen. Of the herbicides, 2,4-D dimethyl amine (60 percent w/w) at the rate of 50 ml and triclopyr butoxv ethyl ester (32.1 percent w/w) at 60 ml, paraquat dichloride (25 percent w/w) 80 ml + 3 g of metsulfuron methyl (20 percent w/ w), glyphosate isopropylamine (41 percent w/w) 80 ml + 3g of metsulfuron methyl (20 percent w/w) diluted in 18 litres of water were found to be effective in controlling C. speciosus. Slashing of the weed followed by spraying of herbicides to wet run off over the stump pith gave quicker control than drenching of theweed directly with herbicides. In another experiment, the optimal rates of 2,4-D amine, and triclopyr butoxy ethyl ester to control the weed by slashing method was evaluated. It was observed that spraying of 40 ml 2,4-D amine and 20 ml oftriciopyr butoxyester diluted in 18 litres of water of spray pump effectively controlled the weed.