Introduction
Japanese MINT (Mentha arvensis vary piperascens) is an aromatic herb of temperate region. The oil and its principal aroma-compound menthol have cooling and gastro-stimulant properties, for which it is used in pharmaceuticals, food flavor, confectionery, cosmetics, beverages and related industries. In India, it is grown over around 50,000ha land. The area has grown enormously during the last 3 years in tarai districts of Uttar Pradesh, and Parts of Punjab and Haryana. Indian has emerged as a large exporter of its oil and menthol to world market, particular to the USA.
Mints favours well-drained, deep, organic, sandy-loam to clay-loam soils of 6-7 pH with copious irrigation. Clayey soils, high pH(>8.50) and frosty locations are unsuitable. Since it is a shallow-feeder, high water table between 60 and 100cm with efficient drainage is favorable. It is a long day plant, grown as a long duration (240 days) annual crop, growing up to 1,000m elevation in subtropical north India. Annual fluctuation in temperature of 40°C and 0°C with sunshine around the growing season is ideal; shade is undesirable.
It is harvested at flowering on dry sunny days. The crop maturity is determined by distillation of crop sample in Clevenger’s apparatus. If it gives is reached in 105-110 days of sprouting for first harvesting and 80-90 days after the first cut is taken for the second crop. The crop is cut 10cm above through sickle and left in the field for 4-6hr for wilting. It loses 50% of its moisture and then chopped into small pieces and distilled in a steam distillation unit. Harvesting on cloudy or rainy day decreases menthol content in its oil significantly. An average of 30 tones/ha of herbage yield in 2 cuts is takes in a year, producing 150kg of oil. Higher yields are obtained from a well-managed plantation. The oil, golden-yellow in colour, is a mobile liquid, contains 70-80% menthol. The oil is dried of adhering moisture and stored in aluminum or mild steel containers. Filled up to the brim and stored in a dry cool godown. Peppermint
Local names
Peppermint (Mentha pipefitter) is an allied mint crop with relatively long- stalked opposite lanceolate leaves. The plants are 50-80cm tall, bearing globular flowering spikies. Its bears purplish blossom in terminal spikes. The common black Mitcham variety (introduced) is vigorous growing hardy plant and prefers cool sub-temperate climate. Since growth and yield of peppermint is not very high in tarai track of Uttar Pradesh, it is not grown here in large areas. It is cultivated on a small scale in Punjab and parts of himachal Pradesh. The cultivation practices are similar to those of Japanese mint. It has lower oil content (0.25%), the average oil yield being 80kg/ha from a fertile land having well-managed plantation. The oil has 50-50% menthol, sweet in taste and of superior odour. It is mainly used in pharmaceutical preparations. It fetches much higher price than oil of Japanese mint. Spearmint
Spearmint(Mentha spicate) is another important mint. Its oil is rich in carvone (65%) content and emits caraway like odor. The oil is useful in dentifrice, confectionery and pharmaceutical products. It bears lanceolate stalkless, light green leaves and narrow, long, terminal flowering spikes with lilac flowers, attaining a height of up to 60cm. Two commercial varieties have been evolved in India. Of them, Punjab Spearmint is an erect growing with quadrangular purply-green, hairy stem, production 20q/ha of fresh herb. It contains 0.57% oil, the oil yield being 120 liters/ha containing 68% carvone. The other variety MSS 5 is relatively vigorous in growth, yielding 250-300q/ha of fresh herb or 150kg of oil from commercial plantations. It is cultivated in smaller area in Punjab and foothills of Uttar Pradesh. It fetches higher price.
Bergamot mint Bergamot mint or lemon mint (Mentha citrate) is a glabrescent aromatic herb, robust in growth like Japanese Mint. It has similar broad ovate leaves but without a distinct inflorescence. The flowering vertices are borne in upper part of the stem in axil of leaves. The oil has an odor reminiscent of lavender oil due to its containing high linalool (45-50%) and linalyl acetate (45%) contents. The yield of herb and oil is similar to Japanese mint. A high-yielding variety, Kiran, produces 150kg of oil/ha, containing 48% linalool. The Cultivation practices are similar to those of other mints. It grows well in subtropical, fertile plains of north India. About 50-60 tones of oil is produced in the country annually, fetching price akin to oil Japanese mint. The oil mainly used in perfumery industry.