Monday 3 November 2008

CROP HUSBANDRY- BETEL VINE CULTIVATION PRACTICES IN KERALA

BETEL VINE (Piper betle)


Betel vine requires a tropical climate with high atmospheric humidity. It can be cultivated in the uplands as well as in wetlands. In Kerala, it is mainly cultivated in arecanut and coconut gardens as an intercrop. The crop grows best on well-drained fertile soils. Waterlogged, saline and alkali soils are unsuitable for its cultivation. The crop also comes up very well in lateritic soils. Proper shade and irrigation are essential for successful cultivation of this crop. An annual rainfall ranging from 200 to 450 cm is ideal. The crop tolerates a minimum temperature of 10ºC and a maximum of 40ºC. Extremely low atmospheric temperature leads to leaf fall. Hot dry winds are harmful.

Varieties
The important types are Thulasi, Venmani, Arikodi, Kalkodi, Karilanchi, Karpuram, Chelanthikarpuram, Koottakkodinandan, Perumkodi, Amaravila and Pramuttan.

Season
There are two important planting seasons. The Edavakodi is planted in May-June and the Thulakodi in August-September.

Preparation of land
Areas with good shade and irrigation facilities are preferred for this crop. The land is dug well and laid out into furrows of 10-15 m length, 75 cm width and 75 cm depth. Such furrows are opened at a distance of 1 m apart. Well rotten farmyard manure and leaves are thoroughly incorporated with the topsoil of the furrows, along with wood ash. High dose of organic manure (20-50 t/ha) is applied to maintain good soil structure, which is essential for the proper development of the root system.

Planting material and planting
Top portions of mature vines (2-3 years old) are used for planting. Healthy cuttings of about 1 m length with three nodes are used as planting material. For planting one hectare, 20000-25000 cuttings are required. Furrows are irrigated prior to planting. Cuttings are planted in holes 20 cm apart in furrows. While planting, one node shall be buried in the soil and the second node should be at the ground level. The soil around the planted cutting must be pressed firmly to encourage quick germination. It is necessary to provide shade to the planted cuttings. Coconut leaves are used as shading material. To prevent excess moisture in the soil, splashing water on the vines by hand is preferable in the early stages. In the absence of rain, light irrigation, four times daily, is given till establishment. Cuttings establish in three weeks time and the first leaf emerges in about a month.

Irrigation and drainage
Betel vine needs constantly moist soil, but there should not be excessive moisture. Hence, frequent light irritations are given. The quantity of irrigation water should be such that the standing water should not remain for more than half an hour in the bed. If waterlogging by heavy rains or excess irrigation occurs, drainage should be arranged immediately. The best time for irrigation is morning or evening.

Trailing the vines and weeding

The cuttings sprout and creep in about a month. At this time, they must be trailed on the standards. Bamboo standards are erected at intervals and linked by tying at heights of 30 cm and 150 cm using coir rope. In the initial stages trailing is done on coir tied for the purpose. Trailing is done further by tying the vines, at intervals of 15-20 cm along the standards loosely with the help of banana fibre. When vines come in contact with standards, they produce adventitious roots using which they cling to support. Trailing is done every 15-20 days depending on the growth of vines. Gardens should be kept clean by weeding and stirring as and when required.

Manuring
Dried leaves and wood ash are applied to the furrows at fortnightly intervals and cowdung slurry is sprinkled. This is repeated till four months after planting when the crop is ready for harvest. Application of different kinds of leaves (gliricidia, mango leaves etc) at monthly intervals is found advantageous for the growth of the vines.

Harvesting

In about 3-6 months time, vines grow to a height 150-180 cm. At this stage branching is noticed in the vines. Leaves are removed along with the petiole with the right thumb. Once harvesting is commenced, it is continued almost every day or week. The interval of harvesting varies from 15 days to about a month till the next lowering of vines. After each harvest, manuring has to be done.

Lowering the vines

Under normal conditions, vines grow to a height of about 3 m in one-year time. When they reach this height, their vigour to produce normal sized leaves is reduced and the crop needs rejuvenation. This is done by lowering the vines down to the ground level at least once a year. Lowering is done during the months of August-September. Before lowering, all the leaves in the basal portion of the vines to a height of 15 cm are removed. Vine is untied from bottom upwards and coiled up carefully and laid flat on ground leaving 2.5 to 5 cm length of top shoots. Soil is put over the portion kept in the soil to about 5 cm thickness. Lowering is followed by light irrigation and manuring.

Plant protection

The insect pests include the mirid bug (Disphincuts politus) which de-saps the tender leaves and shoots, scale insects and mealy bugs (Lepidosaphes and Pseudococcus), which occur on the stems. Insecticidal application is not recommended to avoid toxic hazards. In serious infestations, apply fish oil soap at 1.5% against the mirid bugs and 0.025% quinalphos against the scale insects and mealy bugs. Against scale insects, restrict insecticide application on the stem only. The leaves should be harvested only after 15 days of insecticide application. The treated leaves should be consumed / marketed after thorough washing in water. Among the diseases, the bacterial leaf spot caused by Xanthomonas betlicola is most serious in southern Kerala. The initial symptoms appear as small water-soaked regions, which enlarge and turn dark brown in the centre with yellow halo. Profuse bacterial ooze may be seen on the lower side of the lesion. In severe cases, defoliation and stem injury occur, leading to wilting of the plant. The cultivars Karilanchi, Karpuram, and Thulasi are found susceptible to the disease. Spraying of 1% Bordeaux mixture is recommended to control the disease.

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