Effect of Chemical Weed Control on Growth, Herb Yield and Oil Content of Mentha (Mentha arvensis L.) Across Northern Eastern and Central Highlands of India

A field experiment was carried out during the summer season of 2015 at Crop Research Farm of Sam Higginbottom Institute of Agriculture, Technology & Sciences, Allahabad to study the effect of various weed management options on weed dynamics and production of mentha. In the experiment six treatments namely, propaquizafop 10% EC @ 50 ml/ha, propaquizafop 10% EC @ 62.5 ml/ha, propaquizafop 10% EC @ 75 ml/ha, fenoxaprop-p-ethyl 9.3% EC @ 100 ml/ha, hand weeding and un-weeded control were laid out in Randomized Complete Block Design (RCBD) with four replications. The results revealed that a significantly lower weed density and weed dry matter weight, weed index and higher weed control efficiency were recorded under hand weeding which was found at par to fenoxaprop-p-ethyl 9.3% EC @ 100 ml/ha and propaquizafop 10% EC @ 75 ml/ha. The higher plant height, herbage yield (21.8 t/ha) and dry matter yield (6.00 t/ha) and oil yield (136.9 l/ha) of mentha were also obtained with hand weeding which was found at par to fenoxaprop-p-ethyl 9.3% EC @ 100 ml/ha and propaquizafop 10% EC @ 75 ml/ha. fenoxaprop-p-ethyl 9.3% EC @ 100 ml/ha also resulted in the most effective herbicide against grassy weed and generated maximum net return (Rs. 92303/ha) and benefit: cost ratio (2.30) followed by propaquizafop 10% EC @ 75 ml/ha.