Effect of weather conditions on growth, yield and quality of Menthol mint (Mentha arvensis L.) cultivars transplanted in different years on different dates under sub-tropical climate of North India

Menthol mint (Mentha arvensis L.) is grown as summer season crop in sub-tropical plains of north India for its valued essential oil. The productivity and quality of the essential oil is significantly influenced by weather parameters prevailed during cropping season. The studies conducted to assess the effect of different seasons, cultivars and dates of planting, revealed that growth, yield and quality of menthol mint was significantly better during hot and dry cropping season of 2010 than hot and humid season of 2011. Essential oil content in fresh herb was 39 % higher in 2010 over 2011; resulting 26.2 %, 9.5 % and 37.9 % increase in essential oil yield, menthol content and menthol yield, respectively. Maximum herb, oil and menthol yields were recorded when crop was planted on 15th March irrespective of cropping season and cultivars. Delay in the transplanting resulted in significant reduction in herb, oil and menthol yield. Cultivar Kosi produced maximum essential oil of better quality across different cropping seasons and date of transplanting; cultivar Saksham produced lowest oil during cropping season 2010. Net return in cropping season 2010 was 54.8 % higher than the cropping season 2011. Cultivar Kosi planted on 15th March gave maximum net returns of ₹ 80365 ha-1 in hot and dry cropping season of 2010. Menthol mint prefers hot and dry weather for producing maximum essential oil with better quality and it should be transplanted at early date in mid-March using cultivar Kosi, under sub-tropical climate of north India.