Cultivation Practices

For planting in new area, ground should be cleared or if it is replanting area, old plants should be removed. Shade regulation, terracing and preparation of pits should be done during summer months.Major cultivation practices include Shade regulation , Field preparation , Planting , Weed control , Irrigation, Soil and water conservation, Forking and mulching, Trashing & Earthing up.

Shade regulation

Shade regulation is one of the important practices. It should be attended to during summer (March-April) in the new planting areas and during May-June after the receipt of summer

showers in the existing plantations. If there is thick shade due to dense branches and bigger leaves, chopping off branches should be done to provide filtered light of 40 to 60 per cent of the open area. South-western slopes should be provided with more shade than north-eastern slopes. Shade trees should have small leaves, tap root system and in summer it should not shed leaves. If area is open due to tree fall, planting of tree species viz., karuna ( Vernonia arborea ) Kurangatti (Acrocarpus fraxinifolius), chandana viambu (Toona ciliata), njaval tree, vellakil (Dysoxylum malabaricum) and thelli (Canarium strictum) etc.  should be taken up immediately to protect the plants from direct sunlight. Too much shade or too much openness of area is not advisable for cardamom cultivation as it affects growth and yield.

Main field planting

Cardamom plantation is raised in forests under the shade of tall trees. For raising a new cardamom plantation, the undergrowth of bushes is cleared. When open areas like marshy valleys and grasslands are selected for raising new plantation, shade trees have to be raised before planting cardamom seedlings. The quick growing shade trees like Vernonia arborea and Toona ciliata are generally used for this purpose. Cuttings of this tree are used for planting. But this tree is a host of root knot nematode, which infests cardamom. Other quick growing trees like Albizia can also be used. Useful trees like jack can be used along with wild nutmeg, kurangatti etc.

Spacing

Mysore and Vazhukka: 2 m x 2 m to 3 m x 2 m depending on the fertility of the soil Malabar: 1.5 m x 1.5 m to 2 m x 2 m depending on the fertility of the soil.

The recommended size of pits is 60 cm x 60 cm x 35 cm. The pits are filled with rich topsoil at least two months in advance of planting the seedlings. Application of well decomposed FYM or compost or leaf mould and 100 g of rock phosphate with the topsoil in the pit will help in proper establishment and quick growth of plants. If the selected site is a hill slope, terraces may be formed before digging pits.

Planting can be done with the commencement of southwest monsoon, before the heavy rains. A small pit may be formed inside the pit by scooping out soil at the centre of the pit for planting seedlings. The soil may be put just to cover the rhizomes. Care should be taken to ensure that the rhizomes do not go deep into the soil.

Weed control

Weeds are potential competitors in the consumption of water and nutrients, which will depress the cardamom growth. At the initial stage, if cardamom clump development is not enough, weed growth will be more. Two or three rounds of hand weeding at the plant base during May, September and December/January and slash weeding in other areas are advisable. Use of mammatty (spade) for weeding is not advisable because it will loosen the soil and cause soil erosion. The weeded materials may be used for mulching.

Irrigation

Judicious irrigation during summer months ensures increase in yield by at least 50%. Irrigation is required generally from February to April but at times from January to May depending upon rainfall. But in Tamil Nadu, where the southwest monsoon is not very effective, irrigation during March-August is advisable. This is the period in which development of young tillers and panicles

takes place. If plant suffers during this stage, yield will be reduced. Water may be stored during rainy season wherever possible by constructing check dams without causing much damage to the environment. This water can be used for irrigation. Irrigation can be done through different methods such as pot irrigation, hose irrigation, sprinkler irrigation and drip irrigation depending on the facilities available in the plantation. Pot irrigation or hose irrigation can be done at weekly intervals at the rate of 20-30 litres per clump depending upon the clump size. In case of sprinkler irrigation, with amount of water equivalent to 35 to 45 mm rain at fortnightly intervals is recommended under average conditions. In case of drip irrigation, water at the rate of 4-6 litres per clump per day can be given.

Soil and water conservation

Conservation of natural resources like soil and water is very important for production of the crop. Cultivation of agricultural crops on sloppy hills with intensive operations, which loosen and expose the soil, will increase the soil erosion by water. Planting in trenches across the slope, mulching of soil, diagonal planting and rectangular silt pit opening (1.8 x 0.5 x 0.6 m) in between four plants will help in soil and water conservation in gentle slopes. If slope is steep, construction of stone pitching walls at 10-20 m intervals across the slope and also making water-collecting trenches along the wall will be helpful.

Forking and mulching

Forking the plant base to a distance up to 90 cm and to a depth of 9-12 cm is found to enhance root proliferation and better growth of plants. As far as possible, the entire plantation and particularly the plant base are to be kept under mulch. It is very essential to keep the plant base mulched (5-10 cm thick) except during June to September to reduce the ill effects of drought, for reducing evaporation loss and to maintain optimum temperature.

Trashing

Trashing consists of removing old tillers, dry leaves and leaf sheaths. This operation may be carried out once in a year during June-July, with the commencement of monsoon. These materials can also be used as mulch.

Earthing up

This operation is not required in a normal plantation. However, due to erosion of soil or mismanagement, at times it is noticed that the topsoil covering the plant base is washed away and the rhizomes and roots are exposed and in such situations, earthing up of the plant base with topsoil is recommended during December-January. While carrying out this operation, care should be exercised to ensure that only topsoil is used, and it is evenly spread at the base covering only half the bulb portion of the rhizome. This operation helps to keep the top 10 to 15 cm soil loose and friable enabling easy root penetration and water percolation.

Bee-keeping for better pollination

The main pollination agent in cardamom is honeybee (Apis cerana indica). Maintaining four bee colonies per hectare during the flowering season is recommended for increasing fruit set and production of capsules.