Efficacy and residual effects of topramezone and dicamba herbicide on weed control in selected crops.

Numerous plants are considered weeds in agriculture and reduce crop yield and quality. Eliminating the deleterious effects of weeds is the goal of weed management. Herbicides are one of the methods of weed management despite some being persistent in the soil. Herbicides such as Stellar star whose active ingredients are Topramezone and Dicamba are considered effective selective, systemic post-emergence herbicide in maize. This study was carried out to evaluate the efficacy of Topramezone and Dicamba herbicide and its residual effect on selected succeeding crops. Field and green house experiments laid out as Split-Split Plot (SSP) and Completely Randomized Designs (CRD) were conducted. Stellar star was applied at 1 L/ ha, 2 L/ ha, 4 L/ ha and a no Stellar star Control. Planting of selected crops was done at residual periods of 0, 30, 60, 90 and 120 days. Plant height, biomass weight, number of leaves, grain yield, 100 seed weight, phytotoxicity, damaged and undamaged weeds and weed species present were monitored. Results showed controlled weeds, reduced plant height, bleached leaves and lower yields. Similarities in efficacy was observed; 89.9% between 2 L/ ha and 4 L/ ha treatments and 74.2% between 1 L/ ha and 4 L/ ha. There were highly significant differences (p ≤ 0.01) amongst the treatment means for all parameters. Phytotoxicity effects were highest at 0, 30 and 60 days residual periods. 4 L/ ha had the worst average phytotoxicity score of 8.5 out of 9 (98%) and with the control having the lowest (0%).