Integrated weed management in cotton

The present study was undertaken to assess the effect of integrated weed management practices on weed control and subsequent effects on growth and yield contributing characters of cotton. Weed species found competing with experimental cotton were Cyperus rotundus (40.03%), Portulaca oleraceae (17.77%), Cynodon dactylon (13.70%), Echinochlor columum (10.00%), Convolvulus arvensis (9.25%), Digeria. arvensis (3.70%), Euphorbia hirta (1.85%), Cressia cretica (1.85%) and Chorchorus depressus (1.85%). Highest weed density of 54.25 weeds/m2 was recorded from the plots left unweeded, while the lowest weed density (21.75/m2) was recorded under hand weeding. Among treatments where herbicides were applied for weed control, Dual Gold 960 EC @ 2.5 lit per ha at pre-em treated plots had lowest weed density of 28.75/m2, followed by Dual Gold 960 EC @ 2.0 lit per ha at pre-em with weed density of 32.5/m2. The weed density in plots received pre emergence application of Stomp 330 EC @ 3.75 lit per ha was 38.25/m2, while weed density increased to 41.25/m2 when Stomp 330 EC was applied at reduced rate of 2,5 lit per ha. Highest weed intensity of 25.00 percent was recorded under weedy (control) plots, while the lowest (10.02%) in the plots where weeds were removed manually. Weed intensity in plots treated with pre-emergence application of Dual Gold 960 EC @ 2.5 lit per ha was 13.24 percent, weed intensity increased to 14.97% with decreased dosage in Dual Gold. Likewise, it was observed that weed intensity was increased with herbicidal application at reduced dosage and intensity decreased by increasing the rate of herbicide application. Hand weeding produced maximum control of weeds (74.07%), followed by herbicidal application with Dual Gold 960 EC @ 2.5 lit per ha with 56.66 percent weed control, followed by 36.66 and 33.33 percent weed control percentage recorded under herbicidal applications with Dual Gold 960 EC @ 2.0 lit per ha and Stomp 330 EC @ 3.75 lit per ha, while the lowest weed control percentage of 29.62 was recorded in plots treated with Stomp 330 EC @ 2.50 lit per ha. Maximum plant height of 103.65 cm was recorded, with hand weeding followed by 93.05 and 85.25 cm with pre-emergence herbicidal application of Dual Gold 960 EC @ 2.5 lit per ha and Dual Gold 960 EC @ 2.0 lit per ha, respectively. The plant height of cotton was 80.5cm and 75.20cm in plots where weeds were removed by pre-emergence application of Stomp 330 EC @ 3.75 lit per ha and @ 2.50 lit per ha, respectively. However, the plant height was recorded minimum (66.75 cm) with control. Hand weeding maximum monopodial branches (3.06) were recorded, followed by 2.66 and 2.46 recorded with pre emergence herbicidal application of Dual Gold 960 EC @ 2.5 lit per ha and Stomp 330 EC @ 3.75 lit per ha, respectively. Monopodial branches per plant were 2.34 and 2.32 in plots where weeds were removed by pre-emergence application of Dual Gold 960 EC @ 2.0 lit per ha and Stomp 330 EC @ 2.5 lit per ha, respectively. However, monopodial branches were lowest (1.98) when the crop was left weedy. Sympodial branches of 39.00 per plant were recorded in hand weeding plots followed by 29.00 and 27.30 mean sympodial branches recorded with pre-emergence herbicidal application of Dual Gold 960 EC @ 2.5 lit per ha and Dual Gold 960 EC @ 2.0 lit per ha, respectively. Sympodial branches per plant was 26.35 and 25.80 in plots where weeds were removed by pre-emergence application of Stomp 330 EC @ 3.75 lit per ha and Stomp 330 EC a 2.5 lit per ha, respectively. However, the minimum sympodial branches (20.95) were recorded from the plots in control. In hand weeding plots maximum productive bolls (32.3) were recorded, followed by 23.2 and 22.1 bolls from pre-emergence herbicidal application of Dual Gold 960 EC @ 2.5 lit per ha and Stomp 330 EC @ 3.75 lit per ha respectively. Productive bolls per plant were 21.25 and 21.0 in plots where weeds were removed by pre-emergence application of Dual Gold 960 EC @ 2.0 lit per ha and Stomp 330 EC @ 2.5 lit per ha, respectively. However, productive bolls were minimum (16.25) under control conditions. Maximum seed cotton yield of 3942 kg per ha was recorded hand weeding plots followed by 2992.5 kg and 2565.0 kg per ha seed cotton yield with pre-emergence herbicidal application of Dual Gold 960 EC @ 2.5 lit per ha and Dual Gold 960 EC @ 2.0 lit per ha, respectively. The seed cotton yield per ha was 2137.50 and 2018.70 in plots where weeds were removed by pre-emergence application of Stomp 330 EC @ 3.75 lit per ha and Stomp 330 EC @ 2.5 lit per ha, respectively. However, the seed cotton yield per ha was recorded to its minimum level (1790.0 kg per ha) in plot neither where any herbicidal application was employed, nor any other cultural weed control measure was carried out.