Omesh Thakur
College of Agriculture & Research Station, Gariaband


Introduction:
Mentha (Mentha species) is a aromatic perennial herbs belonging to the family Lamiaceae, mainly distributed in temperate and sub-temperate regions of the world. Mentha is an important essential oil bearing plant rich in Menthol and being widely used in pharmaceutical industries. Mentha has been known from the immemorial time as kitchen herbs and also as the medicinal herb of the ancient human civilization. In India mint is mostly cultivate in Uttar Pradesh & Punjab.

Uses:
The oil is used as a flavouring in toothpastes and as food flavoring in pickles and spices, chewing gum and confectionery, soaps and sauces.

Cosmetic preparations like scents, soaps, after-shave lotions and colognes also contain this oil.

There are four species of Mentha:
  • Menthaarvensis (Japanese mint)
  • Menthapiperita (Peppermint)
  • Menthaspicata (Spearmint)
  • Menthacitrata (Bergamot mint)

Climate: 
Mint can be grown at a temperature of 20-25°C promotes vegetative growth, but the essential oil and menthol are reported to increase at a higher temperature of 30°C under Indian conditions. Peppermint and spearmint cannot be grown profitably in tropical and sun tropical areas, especially those areas with very high summer temperatures (40°C) and the ideal yield is obtained only in humid and temperate conditions. Open, sunny situations without excessive rains during the growing period are congenial for the good growth and development of the oil. Bergamot mint can be grown both in temperate as well as subtropical area. However, the yield is higher in temperate climates.

Soil: 
Well drained loam or sandy loam soils rich in organic matter having soil pH between 6 and 8.2 are ideally suited for its cultivation. In case of acidic soil having pH less than 5.5, liming is recommended. The soil should be free from acidity, salinity, alkalinity and water-logging.

Crop Rotations:
Mentha-Potato, Mentha–Toria, Mentha– Oats (fodder), Mentha-Basmati, Mentha–Wheat–Maize– Potato.

Varieties of Mint:

MAS-1: It is a dwarf variety and is early maturing having 30-45 cm height. It contains 70-80% menthol content, @80 qtl/acre herbage and @50-60 kg/acre oil.

Shivalik: The variety contains 65-70% menthol content, @120 qtl/acre herbage yield and @72 kg/acre oil yield. They are sensitive to fungal diseases.

Gomti: The variety is light red in color. Yield is low as compared with other varieties.It contains 70-80 % menthol content.

Himalaya: The leave size is bigger than other varieties. The variety is rust, blight, mildew and leaf spot resistant. It contains 78-80% menthol content.

Kushal: Developed through tissue culture and gets mature within 90-100 days. The variety is disease and pest resistant. It grows best in semi-arid-subtropical areas. It contains @120-132 qtl/acre herbage yield and @70-80 kg/acre oil yield.

Punjab Spraymint 1: The oil content is 0.57% and major content of oil is Carvone. It gives an average yield of 80-100qtl/acre

Land Preparation: Two or three ploughings are necessary to get a fine seedbed. The field should be free from stubbles and weeds.

Seed Rate: Mints are propagated through the creeping stolons or suckers. In the case of peppermint and bergamot mint, even runners are planted. Stolen are obtained from the previous year’s planting. A hectare of well-established mint, on an average, provides enough planting material for ten hectares. About 400 kg stolons are required for planting one hectare of land.

Planting time &Method of planting:
The best time for obtaining stolons is during the months of December and January.The suckers are laid end to end, 4-5 cm deep in furrows, 45 cm apart and are then covered with soil by planking lightly. For higher biomass production and water saving, planting should be done on 67.5 cm wide beds (two rows) or ridges should be made at 60 cm spacing after broadcasting the suckers. Apply 24 q of paddy straw mulch per acre and apply a light irrigation after planting.

Fertilizer Application: 
Generally, nitrogenous fertilizers @ 80-120 kg P and K at 50 kg P2O5 and 40 kg K2O/ha is required for a good crop of mint.

Irrigation :
Mentha requires frequent but light irrigations. Irrigate at 10 days interval till the end of March and at five or six days interval till the onset of the monsoon. During the rainy season, irrigate according to the need.

Harvesting and Yield : 
The crop should preferably be harvested at the flower initiation stage. If the lower leaves of the plants turn yellow and start shedding, harvesting may be done earlier. Two cuttings can be taken, first in June and the second in September. The yield of the crop is 100-125 quintals per acre of fresh herbs. The fresh herb contains 0.4% oil.

Plant protection

Insect pests

1. Cutworm (Agrotis spp.): Cutworms cut the young plants at the ground-level. They remain hidden near the base of the plants during day-time.

Control: Soil treatment with Phorate 10g before planting.

2. Hairy caterpillars: Hairy caterpillars, if appearing in an epidemic form, cause serious damage by feeding on the leaves and the tender stems. When young, they feed gregariously. The grown up caterpillars may migrate from one field to another.

Control: Application of Thiodan or Malathion @1.7ml/ litre of water

Diseases

Root rot and Stem rot (Rhizoctoniabataticola):
The infected portion shows brown lesions which turn dark and later increase in size. The leaves wither and die.

Control: Infected plants should be uprooted and destroyed. Planting stock should not be from an infected field. Mentha farming should be avoided year after year in the same field