International Journal of Plant & Soil Science

A two-year field experiment was conducted on potato crop to evaluate the bio-efficacy of herbicides, suitable doses and their feasibility with mechanical weed control method in terms of plant height, number of tubers and relative composition of weeds. The experiment was arranged in a randomized complete block design (RCBD) with three replications at the vegetable research farm Department of Horticulture, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India, during the winter season of 2017-18 and 2018-19. Randomly selected five plants were used as a sample for recording plant height and average number of tubers per plant in each plot. Plant height was measured at 30, 45, 60 DAS and at harvest then averaged and expressed in centimetres. However, the average number of tubers per plant was obtained by counting the tubers from the selected plant at harvest. For calculation of relative composition of weeds, by counting the number of weed species at 1.0 m² randomly at one place in each plot at 15, 30, 45 and 60 DAS then expressed in per cent. Amongst the herbicidal weed management treatments, Paraquat dichloride 24% SL @ 2.0 L/ha had a significantly taller plants at 45 and 60 DAS and also produces the highest average number of tubers per plant. With respect to the relative composition of weeds, sedges (Cyperus rotundus L.) contributed the most to total weeds, followed by grasses (Cynodon dactylon L.) and broad-leaves weeds (Chenopodium album L., Parthenium hysterophorus L., Sonchus oleraceus L., Anagalis arvensis L., Oxalis spp., Spergula arvensis L.) at 15, 30, 45 and 60 DAS during both years. It is concluded that the application of Paraquat dichloride 24% SL @ 2.0 L/ha control weeds more efficiently thereby it helps in vigorous plant growth thus ultimately increases the number of tubers per plant.