Mentha arvensis (Menthol Mint) is a source of natural menthol, widely used in flavour, fragrances and aroma industry. India is a global leader in the production and export of menthol mint oil because of concrete research efforts of CSIR. The crop is popular among the small and marginal farmers of Indo-Gangetic plains where the crop covers an area of around 3 lakh hectares. The crop can be planted from the month of January to April and is harvested in the month of June before the onset of monsoon and accordingly 1-2 harvests can be obtained. An essential oil yield of 100-150 kgs from one hectare can be achieved within 3-4 months.

Mint is grown in generally subtropical and subtropical moderate climate regions. It needs long day lengths with warm to hot conditions and cool nights for the right quality of oil. Mint can be cultivated both in tropical and sub-tropical areas. Well drained loam or sandy loam soils rich in organic matter are preferable. It can also be cultivated on both red and black soil.

• Well drained, fertile soils with normal pH are preferable for cultivation of mint species.
• It is better to get the soil analysed at a laboratory that will be able to check for mineral deficiencies and excesses, organic status and carbon ratios.
• Soil preparation has to be done according to good cultivation practices.
• Apply suitable soil preparation practices according to the farming operation — rip, plough, disc, harrow, contour, etc.
• If mechanical harvesting and weed control is envisaged, prepare row widths adapted to the machinery to be used.

Menthol mint and spearmint are propagated by suckers and other species are propagated by runner. In direct sowing method, 4-5 quintals of planting material is required in transplanting of menthol mint and 80-100 kg/ha suckers are required for raising nursery. However, the exact time of direct planting and transplanting of mint species is from 15th January to 15th February.

If required, rooted plantlets can be used for gap filling.

The fields should be applied with 150 kg nitrogen, 60 kg phosphorus and 40 kg potassium for two harvests. NPK @80:40:40 kg are sufficient for one harvest. If the soil sample indicates levels lower than what is recommended, fertilisers should be applied before planting.

Mint requires frequent and adequate irrigation, which is used to supplement rainfall. When the plants are fully developed they are surface irrigated at an interval of 10-15 days and the irrigation should be stopped 10-15 days before harvesting. It is important to keep the soil constantly moist, although well drained. Care has to be taken to prevent waterlogging, especially in winters, as this will restrict its growth.

First sixty days after transplanting are critical and therefore fields should be kept weed-free. Farmers may apply Pendemethalin (1kg a.i /ha) before planting.

Bihar hairy caterpillar and semilooper are few serious pests, which can be managed by application of Ekalux (0.1%).

Generally menthol mint crop takes 85-90 days to harvest, if transplanted. If planted directly through suckers, it may take 110-115 days.

Hydro-steam distillation or steam distillation is required for extraction of the oil from whole plant.

Menthol mint (Two harvest): 200 kg/ha

(Single harvest): 100-125 kg/ha

Cost of cultivation : Rs. 40,000/ha

Gross return : Rs. 1,20,000/ha (single harvest)

Net profit : Rs. 80,000/ha (single harvest)