New practices in the cultivation of the mint, Mentha arvensis in the Indo-Gangetic plains

India is the world's dominant producer of crude Mentha arvensis oil, and exporter of its processed derivative, natural menthol. This status has been achieved through superior product price competitiveness resulting from progressive agronomic improvements that include a transition from cultivation of this mint as a semi-perennial to an annual crop. This paper describes and analyses recent developments in Indian M. arvensis cultivation. Observations were made during 1998/99 and 1999/2000 in the fields of 295 farmers in the central Indo-Gangetic plains area. The criteria recorded included: mint cultivars used; the planting, weeding, irrigation, pesticide application and harvesting schedules; crop health in relation to diseases and pests; yields of the harvested herb and the distilled essential oil; the oil menthol content; and the net income. Most of the farmers used the cultivar, Kosi. The performance and returns of Kosi transplanted in April had proved superior to Kosi and Shivalik suckers and to transplanted Shivalik. The returns from late-transplanted Kosi were in the range of Rupees (Rs) 25 000 to Rs 40 000 ha(-1) (Rs 50 approximate to US $1), similar to those from Kosi suckers and much higher than for both transplanted and suckers of Shivalik. This survey revealed that rotations of rice (Ogza sativa) with chickpea (Cicer arietinum) and mint, and pigeonpea (Cajanus cajan) with wheat (Titicum aestivum) and mint could be profitable in the central Indo-Gangetic plains. They also conserved inputs and were preferable to the conventional rice-wheat rotation. A re-survey in the summer of 2002 confirmed that recommendations made to farmers have led to the adoption of the Kosi and Himalaya cultivars in 80% of the survey region and that 70% of mint cultivation in the area occurs in the summer season.