This study was aimed at determining the effectiveness of different weed control combinations in cotton crop. Treatments included different combinations of water extracts of brassica and sorghum, S-Metolachlor and manual weeding. A randomized complete block design (RCBD) experiment with split-split plot arrangements was laid out; where tillage was kept in main plot, water extract treatments at 12 and 15 L ha-1 in sub-plot and pre-emergence herbicide S-Metolachlor at 0 (Control; no herbicide treatment), 1 and 2 L ha-1 in sub-sub plot. S-Metolachlor at 2 L ha-1 was superior for controlling narrow and broad leaf weed population compared with no application of S-Metolachlor and 1 L ha-1. S-Metolachlor at1 L ha-1 also showed statistically better control of narrow leaf weeds. Water extract treatment at15 L ha-1 gave highest control (22-25%) on narrow and broad leaf weed population than no- water extract treatment. The higher rate (2 L ha-1) of S-Metolachlor treatment significantly produced maximum cotton yield i.e., 3086.3 kg ha-1 compared to S-Metolachlor at its lower rate. Water extracts when applied at the rate of 12 and 15 L ha-1 significantly produced greater yield 5-9% and 8-12% respectively.
Keywords: Cotton; Fruit shedding; S-Metolachlor; Allelopathy