Mint In The Farms.

Mints belong to the genus Mentha, in the family Labiatae (Lamiaceae) which includes other commonly grown essential oil-yielding plants such as basil, sage, rosemary, marjoram, lavender, pennyroyal and thyme. Within the genus Mentha there are several commercially grown species, varying in their major chemical content, aroma and end use. Their oils and derived aroma compounds are traded world-wide.

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The four most commonly cultivated species are:

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?????? Japanese Mint/Menthol Mint (M.arvensis)

?????? Peppermint (M.piperita)

?????? Spearmint (M. spicata)

?????? Bergamot mint (M. citrata)

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All are herbaceous plants, readily sending out runners (rainy season) and stolons (winter), which develop new roots and shoots at the nodes and form plants. The entire aerial shoots together with foliage is a source of essential oil rich in menthol, carvone, linalool and linanyl acetate having use in pharmaceutical preparations and flavour industry.

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For the past four decades, mints are commercially cultivated in India. Of these, the Japanese Mint, yielding menthol is grown extensively in northern India. Other major producing countries are China and Brazil and to a smaller extent Thailand and Vietnam.

3.????????????????? BACKGROUND        

3.1????????????? Origin

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The cultivation of Japanese or corn mint originated from Brazil and China. Subsequently, China and India overtook Brazil and more recently India has taken the leading position in cultivation of this essential oil yielding plant.

3.2????????????? Botanical Description

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Japanese mint is a perennial ascending herb growing about 60-80 cm. in height and under favourable conditions may attain a height upto 100 cm. It is propagated mainly by its stolons . Leaves are lanceolate-oblong, sharply toothed; petiole is small about 5mm. in length. The leaf lamina varies from 5 to 15 cm. The leaf surfaces mainly lower side is covered with dense hairy growth of glandular trichomes. Flowers are borne in axillary and terminal verticillaster , abundant in number , purplish in colour. The flowers are small with corolla measuring 4-5mm., calyx 2-3mm., narrowly deltoid and acuminate. It does not produce seed and propagation is through vegetative means only.

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3.3????????????? Area and Production

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At present, Japnese mint is cultivated in India on about 60,000 ha. of land with estimated production of 12,000 tonnes of mint oil which accounts for about 75% of total menthol mint production in the world.

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The following Table-1 gives estimated area & production of various mint species in India vis-à-vis world production.

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Table-1: Estimated area and production of mint in India and abroad.

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Species

Area (ha.)

Production (tonnes of Oil)

Total world production (tonnes of Oil))

Major Producing Countries

Japanese mint

60,000

12,000

16,000

India,China, Brazil

Peppermint

2,500

200

4,000

USA, France, former USSR, Brazil, India

Bergamot mint

1,200

150

200

USA , Brazil, Thailand

Spearmint

3,000

300

2,000

USA,China, former USSR, India

Source: Essential Oils Association of India (2001), Vision 2005

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3.4????????????? Economic Importance

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Japanese Mint (Mentha arvensis var piperascense) is an aromatic perennial herb, grown as an annual in sub-tropical parts of north India. The over-ground herb (foliage) on distillation yields an essential oil, containing high (75 – 80%) menthol content. The oil has a bitter cooling taste, harsh odour and is the principal source of menthol. It is used in combating cold, used as an ingredient in cough drops and related pharmaceuticals, dentifrices, cosmetics, mouth washes, scenting of tobacco products and flavouring of beverages. Synthetic menthol has also come in market but its volumes are meagre due to high cost of production. Besides, natural menthol is preferred in food and flavour industr

4.1????????????? Demand and Supply Patterns

The Mint oils obtained from Mentha arvensis, Mentha piperita, Mentha citrata and Mentha spicata have put India on the world map. Of these, mint oil and menthol are primarily exported whereas others meet the home requirement of the industry. Despite our quantity of peppermint and spearmint being at par with World Standards, we have not made any headway in export trade because of fierce competition by USA. The latter is also the largest consumer of these oils.        

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The trend in domestic & international prices of oil during the five year period i.e. 1998-2002 is depicted in the graph below.

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4.2????????????? Import / Export Trends?

A large part of the country’s oil production is exported. It meets fierce competition in trade with China. The crop has of late involved a large sector in processing and trade activity in several small towns of U.P. (Rampur, Sambhal, Chandausi, Badaun, and Barabanki). A large number of farmers, traders, distillers and exporters are associated with this activity. The investment in the industry is estimated at Rs.350 crores.

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Table-2: Export of mint oils, menthol and other derivatives from India

(1998-99 to 2002-03).

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Item

1998-99

1999-2000

2000-2001

2001-2002

2002-2003

Q

V

Q

V

Q

V

Q

V

Q

V

Mint oil

926.0

21.2

457.0

25.5

1095.4

39.3

1151.5

48.9

1280.8

52.0

Menthol

6198.4

175.3

7967.5

414.8

8809.0

393.4

7494.7

371.8

8851.0

388.4

DMO

734.0

70.5

648.6

15.3

636.3

18.0

452.1

12.9

505.2

16.2

Total Value

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267.0

-

455.6

-

450.7

-

433.6

-

456.6

Source: Monthly Statistics of Foreign Trade of India, Vol I Export)

Q = Quantity (tonnes) ; V = Value (Rs. crores)

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Fluctuations in price are common. Currently it varies between Rs.350-400 for oil and Rs.600-800 for menthol (July-August and October) but the price is also governed by demand and price prevailing in importing countries and speculations on volumes and crop condition within India.         

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4.3????????????? Analysis and Future Strateg

India has attained position of primary and dominant source of mint oil and menthol in the world market, replacing China to a great extent due to (lower) price structure and comparable quality. At present, the growth in demand of oil and menthol in world trade is slow and unless its demand rises significantly in flavouring sector (where natural products are preferred), there is little scope for any major expansion in cultivation area. However, because of rising input cost and expensive labour in South China, its cultivation there could presumably shrink and consequently Indian mint may find increasing larger market in next several years. There can be significant increase in area of cultivation due to this.

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The country has evolved a number of new high yielding varieties which has helped to maintain India in a lead position. At present, India produces 4000 – 5000 tonnes of DMO annually which is sold at a low price. This has several minor constituents which could be fractionated and marketed at higher price. Similarly, some low value constituents of the DMO (dementholized oil) could be synthesized into high value end products to help industry realize better value of the primary product. At present, Cis – 3 hexanol is fractionated from DMO and exported at a high price. Its production started in 1994-95 and this pushed price of DMO from Rs.50 to 90 in that year itself. There is scope for producing L-limonene, 3–octonol, pure menthone and isomenthone. Similarly, L-menthol, neo-menthol, isomenthone can be converted into high value menthol and esters of menthol, like methyl isovalerate, menthol lactate, methyl salicylate which fetches better price in trade. All this can sustain a high level of cultivation and support export trade. The market demand for pure L-menthol, iso-menthone, L-limonene, neo-menthol and pinene is high.

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5.????????????????? PRODUCTION TECHNOLOGY        

5.1????????????? Agro-climatic Requirements

Japanese mint can be cultivated both in tropical and sub-tropical areas. The mean temperature between 20-400 C during major part of the growing period and rainfall between 100-110 cm. (light showers at planting stage and ample sunshine at the time of harvesting) is ideal for its cultivation.        

Well drained loam or sandy loam soils rich in organic matter having pH between 6 and 8.2 are ideally suited for its cultivation. It can also be cultivated on both red and black soil. In case of acidic soil having pH less than 5.5, liming is recommended.?         

5.2????????????? Growing and Potential Belts

India grows Japanese mint in around 60,000 ha in tarai districts (Rudrapur, Bilaspur etc.) of Uttaranchal and central U.P. (Barabanki, Moradabad, Bareily, Badaun and Lucknow) besides smaller area in parts of Punjab (Ludhiana and Jallandhar).        

5.3????????????? Varieties

The new varieties developed on Japanese mint in the country together with their traits as given in release note or extension literature are presented below:

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Sr. No.

Variety

1.MAS-1

Characteristics given in literature

§ It is a dwarf variety 30-45 cm. in height and early maturing variety.

§?? Less prone to insects due to short height.

§?? Menthol content-70-80%.

§?? Yield: About 200 q/ha. of herbage & 125-150 kg. of oil /ha.

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Sr. No.        

Variety        

2.Hybrid-77

Characteristics given in literature

§?? Early maturing variety.

§?? It is 50-60 cm. in height.

§?? Less prone to diseases viz. leaf spot & rust diseases.

§?? Menthol content-80-85%.

§?? Yield: About 250 q/ha. of herbage & 120-150 kg. of oil /ha.

§?? It is especially well adapted to sandy loam soils and drier climate than that of the tarai region.

3.Shivalik

Characteristics given in literature

(selection from Chinese cultivar)

§?? The recovery of oil from the herb is 0.4 -0.5 %.

§?? Menthol content: 65-70%.

§?? This variety is highly suitable for obtaining second cut through ratooning.

§?? It is particularly grown in tarai region of U.P. & Uttaranchal.

§?? The herbage yield is 300q/ha while the essential oil yield amounts to about 180 kg/ha.

§?? Highly sensitive to the fungal diseases and pests prevailing in the tarai area.

4.EC-41911

Characteristics given in literature

(selection from Russian germplasm)

§??? 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 70% menthol.

§?? Oil is preferred in flavouring food items.

5.Gomti

Characteristics given in literature

§?? It is sturdy, light red in colour.

§?? Menthol content-78-80%.

§?? Yield is less compared to other varieties. It is less adopted by farmers.

6.Himalaya

Characteristics given in literature

? Resistant to rust, blight, mildew and leaf spot diseases.

§??? Crop is good; size of leaves is larger than other varieties.

§??? Menthol content-78-80%.

§?? The yield of herbage is 400q/ha and essential oil is 200-250 kg/ ha.

7.Kosi

Characteristics given in literature

§??? Matures early in 90 days.

§??? Resistant to rust, blight, mildew and leaf spot diseases.

§??? Essential oil content 75-80 % menthol.

§??? Yield: 200-250 kg. of oil /ha.

8.Saksham

Characteristics given in literature

§?? Developed through tissue culture from cv. Himalaya.

§?? Yield: 225-250 kg. of oil/ha. having menthol content more than 80%.

9.Kushal

Characteristics given in literature

§?? New variety developed through tissue culture.

§?? Matures within 90-100 days.

§?? The crop remains free from pests and diseases (particularly rust and leaf blight).

§?? The variety is most suitable for transplanting after wheat in semi-arid –sub- tropical condition of UP and Punjab.

§?? It can withstand waterlogging for few days.

§?? Yield: 300-330 q. /ha. having oil yield upto 175-200 kg./ha.

It is a matter of investigation that inspite of claims of high herb yield, oil yield and menthol content in the oil, the farmers have reaped on an average 1200kg. of oil per ha. for more than last two decades showing a marginal increase over these years.

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5.4????????????? Propagation

Mint can be propagated vegetatively through stolons and runners.?? By and large, most area under the crop is propagated by planting live juicy 8 to 10 cm. long stolons (underground stems) during early spring season. The seed rate used is 400-450 kg. of stolons per ha. and the spacing varies from 40 to 60 cm., depending upon soil fertility and the kind of the intercultural implements used. In northern India, planting of Japanese mint is suitable from first week of February to second week of March.        

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5.5????????????? Production of Stolons

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The plot should preferably be the best piece of land. It should be given high level of FYM during land preparation. Around 200 sq.m. plot is required to produce stolons for 1 hectare. Mature plants of chosen variety brought from a reliable nursery should be planted at 30 X 30cm. The nursery for the stolons is planted in August. The nursery is given frequent irrigation avoiding stagnation of water. Stolons are produced in autumn and are ready for use during the months of January to March. To obtain the stolons , the soil is opened manually or mechanically. These stolons can be used immediately or within a fortnight or so.

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5.6????????????? Planting from Stolons

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The field should be ploughed and harrowed thoroughly and divided into beds of suitable size to facilitate irrigation and make it free from weeds and stubbles. In each bed, lines are opened at a distance of 40 to 60 cm depending upon the variety and inter-culture implement used. The furrows are opened about 5 to 6 cm deep manually or through tractor driven harrow. Within a furrow, stolons are placed in rows at 10 cm. distance and furrows are closed with top soil. The bed is irrigated immediately after placing the stolons. On an average, 4 quintals of stolons are required for planting in one hectare of land. The stolons sprout in about 2 to 3 weeks when planted in February. Generally the planting should be done early depending upon ground temperature.

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5.7????????????? Irrigation

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Ten?? irrigations are given during summer season at intervals of? 10-12 days whereas another 4-6 for autumn crop harvested in late October. In order to obtain luxuriant growth, sufficient fertilizers and water must be applied to mint crop. A minimum water of about 100 mm is required to obtain good crop yield. Water logging during rainy season should be avoided by providing adequate drainage. In case of heavy soils and the soils prone to water logging, it is preferable to cultivate mint on ridges. The frequency of irrigation can also be reduced by 25% through the application of leaf mulches @ 5 t/ha.        

5.8????????????? Nutrition

The recommended dose for chemical fertilizers is Nitrogen? 120 kg, phosphorus 60 kg and potassium 40? kg? per ha. The entire quantity of P and K along with one-fifth of N is mixed with the soil at the time of planting, the remaining four-fifth of N is given as top-dressing twice for each harvest in available split doses. About 20 tonnes of well-rotten FYM, 150 kg DAP and 100 kg MOP per hectare are applied at the time of planting. Subsequently, half of N in the form of calcium ammonium nitrate or urea is applied in 2 split doses at 30 and 60 days after planting and similar quantities for ratoon crop at 25 days and 45 days of the harvest.        

5.9????????????? Intercultural Operations

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By and large, 4 to 14 weeks after planting is crucial period for weed control. The crop requires intensive weeding and this is the most expensive cultural operation which contributes to a higher yield of the crop. Weeding with hand or mechanical hoes within the first six weeks of planting does control weeds. This process can be repeated once and rarely twice at an interval of about two to three weeks, after the first weeding. Since weeding and hoeing accounts for 30% of the cost of cultivation, use of wheel hoes either driven by hand or bullock drawn helps in reducing cost on interculture.? Several pre-and post application of weedicides are recommended but these weedicides cannot control monocot weeds after the rainy season. Therefore best method is to combine manual, mechanical and chemical methods. Some of the effective herbicides includes Oxyflurofen (0.5 kg a.i. / ha), Pendimethalin (0.75 a.i. / ha), Simazine and Atrazine (1 kg a.i. / ha). The best procedure is to first apply a weedicide followed by manual or mechanical weeding at 8 to 10 weeks when mulching should also be applied.

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5.10????????? Crop Rotation

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The rotation of mint crop with other food crops is found to be a good way of controlling weeds. Continuous cropping of any of the mints is not advisable.The best rotaion is Mint : Rice and Mint : Potatoes and Mint : Vegetables : Peas etc. depending upon cropping system followed in the region.

5.11????????? Plant Protection Measures

Hairy Caterpillar(Diacrisia obliqua)

Nature of damage
The caterpillar starts eating the under-surface of the leaves.        

Cutworms(Agrotis flammatra)

Nature of damage
Young plants are damaged at the collar region during spring season.        

Red Pumpkin Beetle(Aulocophora foevicollis)

Nature of damage

The pest feeds on the growing leaves and buds.        

Mint Leaf Roller(Syngamia abrupatalis)

Nature of damage
	
The caterpillar folds the leaf in the form of a roll and feed inside the leaf tissue during August-September. The edges of the leaves are held together with silk-like filaments.        

5.11.2??? Diseases

Stolon Rot(Macrophomina phaseoli )

Symptoms

·???? During rainy season, stolon rot occurs on the underground parts; the infected stolons show brown lesions which enlarge and turn black, resulting in a soft decay.

Control

·???? Crop rotation.It is better to follow 3-year-crop rotation with rice, wheat and mint.

·???? Treatment of the stolons with 0.25% solution of Captan or 0.1% Benlate, 0.3 % Agallol solution for 2 to 3 minutes before planting is a preventive measure.

Fusarium Wilt

(Fusarium oxysporum)

Symptoms

·?? Affected leaves turn yellow, curled and finally dry.

Control

·?? Application of Benlate, Bavistin and Topsin.

Leaf blight

(Alternaria sp)

Symptoms

·??? Cause loss of foliage during summer season.

Control

·?? Application of copper fungicide.        

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5.12????????? Harvesting and Yield

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The crop planted through stolons in January and February is harvested twice i.e. in June and October months. The first crop is harvested after 100-120 days of growth and the second harvest in about 80-90 days following the first harvest. The fresh herbage at harvesting stage contains 0.5 to 0.68% of oil and is ready for distillation after wilting for 6-10 hrs. The wilted crop is cut 10cm. above the ground by means of a sickle on bright sunny days, since harvesting on cloudy or rainy days decrease the menthol content in the oil.

Control · Application of copper fungicide. 5.12 Harvesting and Yield

The crop planted through stolons in January and February is harvested twice i.e. in June and October months. The first crop is harvested after 100-120 days of growth and the second harvest in about 80-90 days following the first harvest. The fresh herbage at harvesting stage contains 0.5 to 0.68% of oil and is ready for distillation after wilting for 6-10 hrs. The wilted crop is cut 10cm. above the ground by means of a sickle on bright sunny days, since harvesting on cloudy or rainy days decrease the menthol content in the oil. ?

The average yield is 20 tonnes of fresh herbage per ha. in two harvests , which, in turn, yields around 250 kg. of oil in a year.         

6.????????????????? POST HARVEST MANAGEMENT        

6.1????????????? Storage of Herbage

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. There would be some reduction in oil yield if wilted herbage crop is stored for a longer period of 2-3 days. As such, storage of herbage for a longer period is not recommended.

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6.2????????????? Distillation

The recovery of oil from the herb is 0.5-0.8%. Oil is?? obtained through steam distillation. The oil is of golden yellow colour, containing not less than 75% menthol. The duration of steam distillation is 2-2.5 hours for complete recovery of the oil. About 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

The fresh or semi dried herbage is placed in a tank and 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.

6.3????????????? Purification of Oil?

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. Treating with anhydrous sodium sulphate and decanting removes any remnant moisture in the oil. The whole process is highly critical. Steam rectification process may be applied in case the colour of the oil changes due to rusting.

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6.4????????????? Storage & Packing of Oil

PVC drums of good quality (20-200l capacity) and galvanized iron (GI) drums or aluminium containers are suitable for short and long term storage respectively. The containers should be kept in cool and dark place.

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