Mint Area Under Cultivation South of Himalayan range covering the states of Punjab, Himachal Pradesh, Haryana, Uttar Pradesh and Bihar. The districts where mint is a predominant crop of winter-rabbi season are Moradabad, Badaun, Rampur, Nainitat, Udham Singh Nagar, Bareilly and Basti in the tarai region and Barabanki, Sitapur and Lucknow in the Central Uttar Pradesh, Jullandhar in Punjab and Ambala (Narayangarh) and Yamunanagar in Haryana and Muzaffarpur in Bihar.
Botanical Name : Mentha arvensis Family : Laminaceae Plant Discription : It is a perennial herbaceous plant with the root-stock creeping along or just under the ground surface. It has a rigid branching, pubescent 60-90 cm tall stem bering aromatic leaves.
Centre of Origin : Mediterranean regions Pollination System : Cross pollinated Chromosome No. : 2n=96
Mint Diseases Stolon Rot (Macrophomina Phaseoli) The disease causes rotting of the underground stem and death of the entire plant. One of the main damages caused by the disease is the reduction in the production and rotting of the stolons by the end of the cropping season. Control : The disease can be controlled by proper crop rotation. Mint should not be planted continuously in those areas where attack of stolon-rot is observed. It is better to follow 3-year-crop rotation with rice, wheat and mint. It is safer to discard all the diseased stolons while planting and treat the stolons with 0.25% solution of Captan or 0.1% Benlate.
Root Rot (Thielavia Basicola; Rhizoctonia) Numerous dark brown necrotic spots appear on stolons and roots Control : It is safer to discard all the diseased stolons while planting. The stolons should be pretreated with 0.25% solution of Captan or 0.1% Benlate
Leaf Spot (Corynespora cassiicola; Curvularia lunata; Alternaria spp) Small dirty brownish necrotic spots are observed on the leaves and twigs leading to defoliation Control : Treating the stolons with 0.25% solution of Captan or 0.1% Benlate or spraying with 0.3% Copper Oxychloride is recommended.
Fusarium Wilt (Fusarium Oxysporum) The leaves of the affected plants turn yellow, curled and finally dry. Control : Benlate, Bavistin and Topsin can be used to control the disease.
Root knot (Meloidogyne Incognita, M. Javanca) The nematode affected plants show stunted growth with yellowing of the leaves. Control : Application of neem cake during planting reduces the nematode population.
Rust (Puccinia Menthae) Golden brown spots are observed on the leaves and twigs. The leaves turn yellow and fall off. Control : Spraying the crop with 0.3% Copper fungicides immediately on the appearance of the disease is recommended. Early harvest of the crop during May is suggested so as to decrease the losses due to falling of leaves.
Powdery Mildew (Erysiphae Cichoracearum) Powdery white patches on the upper and lower surfaces of the leaves and stems are observed. Under favourable conditions, the disease causes severe loss due to defoliation. It also reduces the oil content up to 50%. Control : Spraying Sulphur formulation or fungicide like Karathen-WD is recommended. Spraying should commence as soon as the disease appears in the field and should be repeated every 10-15 days.
Mint Harvesting The mint crop herbage is harvested when the field is dry and weather is bright and sunny. A simple way to judge the maturity is to see whether the lower leaves have started turning yellow or when the plant starts flowering. The yellowness of lower leaves indicates that any further delay in harvesting may cause loss in the yield due to falling of the yellow leaves. The usual method of harvesting consists of cutting the green herb by means of sickle from 2-3 cm above the ground. The crop planted with stolons in January and February is harvested twice and that planted with seedlings during March and April is harvested once. The stolon planted crop is first harvested after 100-120 days of growth in the month of May. The second harvest is taken between 60-75 days following the first harvest. The transplanted mint crop is harvested in June or July.
Yield The yield of herbage from a mint crop depends upon a number of factors. On an average, 20-25 tonnes of green herb per hectare can be obtained in three cuttings yielding 125-200 kg of oil/ha.
Uses Menthol mint essential oil is the main source of natural menthol. The dementholised oil (DMO) is reconstituted to produce oil similar to Mentha piperita oil. Several of the many dozens of terpenes present in the essential oil are valuable compounds that find uses in the cosmetic and pharmaceutical industries. Menthol itself is used as a flavouring agent mouth-related produces such as fresheners, tooth pastes and chewing gums, etc. Menthol mint oil because of its antimicrobial properties enhances the shelf of edible products and grains. Menthol mint oil is an essential ingredient of the ointments, pain balms, lozenges and syrups. It is also used in cosmetic preparations, colognes, deodorants, cosmetics, etc. In India, menthol and mint oil are extensively used in betel (pan) related industries.
Mint Intercultural Operations Weed Control Weeds must be removed in the initial period when it is easier to enter the field. Weeding with hand or mechanical hoes within the first six weeks of planting can help in the control of weeds. This process can be repeated once or twice at an interval of about two to three weeks, after the first weeding. Since weeding and hoeing accounts for 30% of cost of cultivation, use of wheel hoes either driven by hand or bullock drawn helps in reducing cost on interculture. Weedicides cannot control all the variety of weeds. Therefore best method is to combine manual, mechanical and chemical methods. Some of the effective herbicides include Oxyflurofen (0.5 kg a.i. / ha), Pendimethalin (0.75 a.i. / ha), Simazine and Atrazine (1 kg a.i. / ha) [a.i. = active ingredient]. The best procedure is to first apply the weedicide followed by manual or mechanical weeding at 8 to 10 weeks when mulching should also be applied.
Crop Rotation Continuous cropping of any of the mints is not advisable, as it results into considerable increase in the weed population, soil-borne diseases and insect problems. One of the best methods of weed control in mint is to follow a suitable crop rotation. Rotation of mints with transplanted rice minimizes weeds interference, helps in reducing the soil-borne diseases, fungal pathogens and the insects. In the districts of Lucknow, Barabanki, Sitapur, etc., the best rotation is rice-potatotransplanted mint. In areas where rice is not a popular kharif crop, any other food crop which requires clean cultivation can be included in rotation. Rotations for Mint Cultivation in India Rotation of the Early Mint
Rotation of the Transplanted Mint
3. Maize/rice-vegetable pea-mint
4. Maize/rice sugarcane-mint
Intercropping Mint as a minor crop can be intercropped with some major crops. To inter crop sugarcane and mint, sugarcane is planted in the spring in February. The row to row distance of sugarcane is kept at 90 cm. A few days after planting of sugarcane, stolons of mint are planted. While sugarcane continues to grow, the mint is harvested in the month of May. Usually the fertilizer would be applied at double the rate in mint-sugarcane intercropping fields. Leguminous crops, maize, sunflower, wheat and onion or garlic can be intercropped with mints. In such intercropping systems, planting of mint stolon and transplanting of onion / garlic should be done simultaneously. Intercropping of legumes is particularly profitable with transplanted mints. Besides the additional yield of legume grain, there is benefit from biological nitrogen fixation that occurs in the root nodules of leguminous plants. If wheat is sown late, mint stolons can be sown between the wheat lines. Both wheat and mint will grow together. Wheat will be harvested and subsequently mint will take over.
Mint Irrigation To obtain luxuriant growth, sufficient fertilizers and water must be applied to mint crop. A minimum water requirement of about 100mm is required to obtain good yield. The crop should be irrigated after the monsoon during September, October and November. The field requires irrigation at an interval of two weeks from January to March while irrigation at ten days interval are sufficient from April to June and water logging is to be avoided by providing adequate drainage. In case of heavy soils and the soils prone to water logging, it is better to cultivate mint on ridges. Citronella distillation waste and sugarcane leaf mulches can be used for control of weeds, soil moisture conservation and control of soil temperature. The frequency of irrigation can also be reduced by 25% through the application of these mulches @ 5 t/ha.
Mint Manuring & Fertilization The major essential oil contents are located in the leaves of mints. More the leaves, the better is the yield from crops. The vegetative growth for the higher production of leaves can be stimulated by the application of essential plant nutrients to the soil or to the plant directly. The recommended fertilizer dose per hectare by CIMAP is as followsDuring land preparation
FYM 25-30 100 kg Urea Tonnes 300 kg SSP 60 kg MOP
1 dose 5 weeks after planting
2 dose 5 weeks after first application
3 rd dose immediately after harvest
4th dose 5 weeks rd after 3 application
Urea 50 kg
Urea 50 kg
Urea 50 kg
Foliar spray of urea @ 2% is also advisable especially late in the season when top dressing of soil is difficult. This technique should also be used in the crops of mint grown in sandy soil. It is also advisable to spray on foliage 0.5% FeEDTA to promote photosynthetic capability of the leaves by prevention of chlorosis.
Mint Pests Mint Leaf Roller (Syngamia Abrupatalis) The caterpillar folds the leaf in the form of a roll and feed inside the leaf tissue. The edges of the leaves are held together with silk-like filaments. Leaves get rolled in August September Control : Thiodan @1.5ml/litre of water should be sprayed at weekly intervals. Two-three sprayings are sufficient to control the pest.
Red Pumpkin Beetle (Aulocophora Fovicollis) Leaves and buds are eaten away Control : Malathion spray @1ml/litre of water is effective.
Cutworms (Agrotis Flammatra) Pest damages the young plants at the collar region during spring season. Control : Soil treatment with Phorate 10G before planting the crop is recommended.
Hairy Caterpillar (Diacrisia Obliqua) The caterpillar starts eating the under-surface of the leaves. And the leaves are damaged Control : Spraying of Thiodan or Malathion @1.7ml/ litre of water is recommended as control.
Mint Planting Planting from Stolons In a nursery sown in August with mature plants, the stolons become available for planting during December - January. The field should be ploughed and harrowed thoroughly and divided into beds to facilitate irrigation and free of weeds and stubbles. In each bed, lines are opened at a distance of 50 to 70 cm depending upon the variety to be cultivated. The furrows are opened about 5 to 6 cm deep manually or tractor driven harrow like instruments. Within a furrow, stolons are placed end to end and furrows are closed with soil. The stolons sown bed is irrigated immediately. On an average, 4 to 5 quintals of stolons are required for planting of one hectare of land. The stolons sprout in about 3 to 4 weeks when planted in January and 2 to 3 weeks when planted in February. Generally the planting should be done as early as possible in January to February.
Planting from Seedlings The field should be prepared to a fine tilth and divided into beds of convenient sizes. The beds to be transplanted with mint should be flooded with water. The seedlings to be used should be dug out from the plantlet nursery. The fresh seedlings of about 9 - 15 cm height should be transplanted at a spacing of 40 x 10cm. Transplanting should be completed between the month of March and mid of April. Transplanting of mint seedlings later than 15th April should be avoided.
Mint Post Harvest Technology Storage of Herbage Some reduction in oil yield occurs if herbage is stored for a longer period of time. Storage of herbage for a period longer than a weeks is not recommended.
Distillation To obtain the essential oil mint, the fresh or semi dries herbage places in a tank treated with passing steam under pressure. The steam that comes out of the tank is then passed through a condenser. The condenser receiving the steam, carrying the oil extracted from the herbage in the tank is kept constantly cool by circulating cold water over/around it. The condensed oil and water mixture is collected in a receiver. Since the water and oil have different densities, oil floats on the surface of the water in the receiver. The oil is skimmed off and collected. The oil that is skimmed off must be cleaned of traces of water that it may carry. For this purpose, a separator funnel is used. Any remnant moisture in the oil is removed by treating with anhydrous sodium sulphate and decanting. The whole process is highly critical in the realisation of the potential yield of the crop. Distillation of the oil is an energy experience process. Simple treatments of the herbage can reduce the total energy requirement for distilling the crop. Mint herbage should be shade dried for about a day before it is distilled. Care should be taken so that decomposition of the herbage does not initiate during the drying process. The distillation requires a source of steam. A high pressure boiler is used for generating the stream. The size of the boiler depends upon the size of the tank charged with herbage and the number of such tanks connected to the boiler. The tank for the charging of the herb should have a detachable lid at the top. Such an arrangement permits form packing of the materials in the tank from the top. Mild steel is used to construct such tanks. The lid has to be air-tight. A rubber gasket helps in making the contact between the lid and tank air-tight. Each tank has an inlet and outlet for the steam and also an outlet for draining out of any left over water in the tank. Condensers can be of several kinds. Tubular types of condensers prove efficient. The tubes in the condensers should be of stainless steel or aluminum. The receivers are so designed that water can be drawn off from the bottom by means of pipe. The oil and water collected from receiver can be separated by use of the glass or the metallic separators. The distillation of herbage should be carried out for at least two hours although 80% of the oil is received in the receiver in about one hour's time. The oil that is received later is richer in menthol.
Directly-fired Distillation Tank This equipment is suitable for small farmers. The lower part of such tanks is filled with water. The water area is separated from the distillation area by a plate. The upper portion is filled with herbage. The tank is heated from the bottom. The steam produced from the water passes through the herbage and carries the oil and water vapour through the condenser to the receiver.
Mint Propagation Mint can be planted in the field in the following ways : 1. by means of underground vegetative parts called suckers or stolons , 2. through propagules/ seedlings. Where mint is to be planted early in the season, stolons are used as the planting material. 3. In case of spearmint, pepper mint and bergamot mint, sometimes runners are also used for planting. 4. In the case of late planting, first the stolons are densely planted in nursery to produce propagules / plantlets / seedlings which in turn are transplanted in the field.
Production of Stolons The plot should preferably be the best piece of land. Around 200 Sq. M Plot is required to produce stolons for 1 hectare. Mature plants of chosen variety brought from a high quality nursery/ CIMAP should be planted at 30 X 30 cm or should have been produced by farmer himself. Care should be taken that the mother plants of the area of previous crop from which they are to be taken should not be allowed to produce seeds; the flowers if formed should be deliberately removed. This way purity of the planting material will be maintained. The nursery for the stolons is planted in August. The nursery is given frequent irrigation avoiding stagnation of water. Stolons are ready for use during the months of December and January. To obtain the stolons under the ground in the nursery, the soil is opened manually or mechanically. The stolons can be used immediately or within a fortnight or so.
Production of Seedlings The land to be chosen to raise the seedling nursery should also be of good quality soil and well drained. About 200-sq. m of land is required to produce seedlings for planting one hectare of land. In the late February or early March, the nursery for raising the seedling is sown. The stolons are dug out from the nursery and are chopped to pieces of about one inch size. The seed bed in which the stolons pieces are sown should have sufficient quantities of farmyard manure (FYM). Such bed is filled with water and puddled. The chopped stolons are further broadcast into the beds. @ About 100 kg/ 200 sq. m of seedbed. To speed up the growth of stolons, they should be covered with some soil and mulching material. The stolons generally sprout in about two weeks time. The plants bearing upto six leaves should be chosen for transplanting in late March to early April
Mint Soil & Climate Soil Loamy Well-drained soils with good water holding capacity and rich in organic matter are better suited Mint crop does not tolerate water stagnation having a pH 6.5-8.0. Climate Open sunny situation during the growing period is favourable. Japanese mint can be grown in all tropical and subtropical areas. Bergamot mint can be grown even in temperate climate. Excessive rains and damp winters which cause root rot. Peppermint and spearmint cannot be grown 0 profitably in tropical and sub-tropical areas, especially with very high summer temperature (41 C).
Mint Varieties Japanese Mint or Menthol Mint ( Mentha arvensis) Variety
The plants are dwarf and early maturing. This variety gives 50% more oil yield with higher menthol content (80-85) and yields 200 q/ha of herbage and 125 kg oil / ha .It should not be used when ratooning is to be practiced.
The plants are somewhat taller than MAS-1. This variety shares many of its characteristics with MAS-1 and is tolerant to several fungal diseases including leaf spot and rust diseases. The essential oil has more than 80% of menthol. Kalka matures early. The crop of Kalka yields about 250 q/ha of herbage and 150 kg oil/ha. The variety Kalka is not recommended for ratooning. It is especially well adapted to the areas adjoining Lucknow, Sitapur and Barabanki where soils are sandy loam and climate is somewhat drier than that of the tarai region.
It is an introduction from China. This variety is highly suitable for obtaining second cut through ratooning. The herbage yield is 300q/ha while the essential oil yield amounts to about 180 kg/ha with a low menthol content (70%). Shivalik is highly sensitive to the fungal diseases and pests prevailing in the tarai area.
This variety yields high amount of essential oil and is not susceptible to pests and diseases. Like Shivalik, Himalaya can be ratooned for two cuts of herbage. Much like MAS-1 and Kalka, it can be used in areas and conditions where only one cut of herbage can be taken. The yield of herbage is 400q/ha and essential oil is 250 kg/ ha. Its oil is of high quality with menthol content of 80%.
It is a tall vigorous compact growing variety. It produces 762q/ha of fresh herb, 468 kg oil/ha containing 81.5% menthol (obtained from 3 cuts). It is highly resistant to rust diseases.
This is an erect type variety, which is less affected by rains. It produces 236.5 q/ha of herbage and 125.2 kg/ha of oil with 705 menthol. This oil is preferred in food flavours.
Spearmint (Mentha spicata). MSS-1
It is a selection from spearmint cultivars introduced from USA. It produces fresh herbage of 535q/ha and yield 253 kg of oil in 3 cuttings containing 60% carvone.
It is a selection from MSS-1, which yields 690q/ha of oil in 3 cuttings. It has 70% of carvone in the oil.
It is an erect growing variety producing 209 q/ha of herb containing 0.57% oil. The oil yields 119.29 litres/ha containing 68% carvone.
Bergamot Mint (Mentha citrata) Kiran
The variety produces 239 kg of oil with 48% linalool, over 172 kg and 39% linalool over parent cultures.