PLANTATION CROPS

 
ARECANUT

Arecanut palm (Areca catechu L.) is cultivated primarily for its kernel obtained from the fruit which is chewed in its tender, ripe or processed form. Arecanut belongs to the family Palmae. It is native of Malayan Archipelago, Philippines and other East Indian Islands. Commercial cultivation is confined only in India, Bangladesh and Sri Lanka. Kerala, Karnataka and Assam account for more than 90 per cent of the total area and production in our country.

Arecanut production in India has now almost reached a level of self-sufficiency. Uses for Arecanut other than chewing are negligible. Its export prospects are also very much limited. Therefore, the present policy is not to expand the area under arecanut, but to adopt intensive cultivation and take up replanting of the aged and unproductive gardens. Inter and mixed cropping in arecanut gardens is advocated to augment the income from the existing arecanut garden.

It is a monoecious palm and its inflorescence is spadix produced in the leaf axil and is completely enclosed in a sealed boat shaped spathe. The spadix is having a main rachis divided subsequently into secondary and tertiary rachis. It is a cross pollinated crop and fruit set normally varies form 12.0 to 40.0 per cent and the time taken from full bloom to maturity of the fruit ranges from 35 to 47 weeks.

Climate and Soil:

The arecanut palm is capable of growing under a variety of climatic and soil conditions. It grows well from almost sea level upto an altitude of 1000 metres in areas receiving abundant and well distributed rainfall or under irrigated conditions. It is grown in soils such as laterite, red loam and alluvial soils. The soil should be deep and well drained.

Varieties:

There are few local varieties known by the name of the place where they are grown and are furnished below: -

Name of the local variety

Place where grown

South Kanara

Dakshina Kannada district and Kassargod district of Kerala

Thirthahalli

Malnad area of Karnataka

Sreevardhan

Coastal Maharashtra

Mettupalayam

Coimbatore District

Mahitnagar

West Bengal

Kahikuchi

Assam

Central Plantation Crops Research Institute, Regional Station, Vittal has released three improved cultivars, they are:

Name of the cultivar

Characters

Mangala

An introduction from China (VTL-3) early bearing, higher fruit set, higher yield (10 kg ripe nuts/palm/year), semitall variety

Subangla

A selection from Indonesia (VTL-11), yield 17.5 kg of nuts/palm at the age of 10 years.

Sreemangala

A selection from Singapore (VTL-170), yields 16.5 kg/palm at the 10th year.

Selection and raising of planting materials

Collection of seednuts should be confined to high yielding palms which commence to bear early as well as those which give more than 50 per cent of fruit set. From these selected mother palms, fully ripe nuts are alone collected. All undersized and malformed nuts must be rejected. Heavier seednuts (above 35 g) within a bunch are alone selected, as they give higher percentage of germination and produce seedlings of better vigour than lighter ones.

The selected seednuts are sown immediately after harvest, 5 cm apart in sand beds under partial shade with their stalk ends pointing upwards. Sand is spread over the nuts just to cover them. The beds may be watered daily. Germination commence in about 40 days after sowing and the sprouts can be transplanted to the second nursery when they are about three months old. At this stage, the sprouts might have produced two to three leaves.

The Secondary nursery beds of 150cm width and of convenient length are prepared for transplanting the sprouts. The sprouts are transplanted at a spacing of 30cm x 30cm with the onset of monsoon. Partial shade to the seedlings can also be provided during summer by pandal or growing banana. Care should be taken to drain the nursery beds during the monsoon and to irrigate them during the dry months. Weeding and mulching should be done periodically. Seednuts can also be sown in polythene bags (25 x 15cm size, 150 gauge) after filling the bags with potting mixture containing 7 parts of loam or top soil, 3 parts of dried and powdered farm yard manure and 2 parts of sand.

The seedlings will be ready for transplanting to the mainfield when they are 12 to 18 months old. Seedlings having 5 or more number of leaves should be selected. The height of seedlings and the time of planting has a negative correlation with the subsequent yield of the plant. Hence shorter seedlings with maximum number of leaves are remove with a ball of earth for transplanting. If the seedlings are raised in polythene bags, these can be straight way transported to any distance without much damage.

Planting

The planting is done during May –June with the onset of monsoon. Arecanut plants need adequate protection from exposure to the south western sun as they are susceptible to sun-scorch. Proper alignment of the palms in the plantation will minimise sun scorching of the stem. In the square system of planting at a spacing of 2.7m x 2.7m, the north south line should be deflected at angle of 35o towards west. The outermost row of plants on the southern and south-western sides can be protected by covering the exposed to with areca leaves or leaf sheaths or by growing tall and quick growing shade trees.

Pits of 90x90x90cm are dug and the pils are filled with a mixture of top soil, powdered cowdung and sand to a height of 50 to 60cm from the bottom. The seedlings are planted in the centre of the pit, covered with soil to the collar level and pressed around. A shade crop of banana can be raised to give protection to the seedlings from sunscroch.

Manures and fertilisers

Adequate supplies of plant nutrients in the soil throughout the life of the crop is essential to get high yield. Hence, an annual application of 100g Nitrogen, 40g Phosphorous and Potash in the form of fertilizer and12kg each of green leaf and compost or cattle manure per bearing palm is recommended. Under rainfed conditions, half the quantity of fertilizers may be applied in April-May and the remaining quantity in September-October. Under irrigated condition, the first dose of fertilizer is applied only in February. Green leaf and compost can be applied in single dose in September-October. Irrespective of the age of the plants, full dose of green leaf and compost or cattle manure may be applied from the first year of planting itself while one-third of the recommended quantity of fertilizers in the first year, two-third in the second year and the full dose from the third year onwards. The first dose of fertilizers may be broadcast around the base of each plant after weeding and mixed with the soil by light forking, while the second dose is done in basins around the palm dug to a depth of 15 to 20cm and at 0.75 to 1m radius. In acidic soils, required quantity of the lime may be applied during the dry months and forked in.

Irrigation and drainage

The palm should be irrigated once in four to seven days depending on the soil type and climatic factors. In Kerala, arecanut gardens are irrigated during dry months once in seven or eight days during November-December, once in the six days during January-February and once in 3-5 days during March, April and May. Adequate drainage should be provided during monsoon since the palms are unable to withstand waterlogging. Drainage channels should be 25 to 30 cm deeper than the bottom of the pits to drain excess water from the plot.

Harvesting and processing

The stage of harvesting depends on the type of produce to be prepared for the market. The most popular trade type of arecanut is the dried, wholenut knows as chali or kottapak. Fully ripe, nine months old fruits having yellow to orange red colour is the best suited for the above purpose. Ripe fruits are dried in the sun for 35 to 40 days on drive levelled ground. For drying dehusking, sometimes fruits are cut longitudinally into two halves and sundried for about 10 days, the kernals are scooped out and given a final drying.

Another form of processing is by making Kalipak. The nuts of 6 to 7 months maturity with dark green colour are dehusked cut into pieces and boiled with water of dilute extract from previous boiling, a kali coating is given and dried finally. Kali is the concentrated extract obtained from boiling 3 to 4 batches of Kalipak. Many varieties of scented suparis are now prepared by blending the dried, broken bits of arecanut with flavour mixtures and packed.

Dehusking of arecanut is traditionally done by skilled manual labour with the help of tool which has a sickle shaped small pointed blade fixed on a plant. A simple device for dehusking arecanut, developed by CPCRI, Kasargod can also be used. The main advantage of this device is that any unskilled person can operate it. The outturn is about 60kg husked nuts in case of dried nuts and 30kg in case of green nuts if one person operators the device for a day of 8 hours.

Yield:

More than 10 kg of ripe nuts per palm at the 10th year is considered as normal yield in any plantation.

Plant protection:

Important diseases and pests affecting arecanut are given below: -

Pest/diseases

Symptoms

Control Measures

Pests

Mites (Raoiella indica)

(Oligonychus indicus)

Adults and young ones suck the lower surfaces of the leaves, causing them to turn yellow and bronzed in appearance

Spray the lower surface of leaves with dicofol 0.05%

Spindle bug

(Calvalhoia arecae)

Adults and young ones suck the sap from the tender spindle resulting in loss of vigour and consequent death

Place 2 g of phorate granules taken in perforated polybags in the inner most leaf axils.

Inflorescence caterpillar

(Tirathaba mundella)

Caterpillars feed on the flowers and clamp the inflorescence into a wet mass of frass with silky threads

Infected spadices may be forced open and sprayed with malathion 0.05%

Diseases

Koleroga or mahili

(Phytophthora arecae.)

Water-soaked lesions appearing on the nut surface near the perianth spread over the other parts giving the nut a dark green colour. Infected nuts shed without perianth.

Spray 1% Bordeaux mixture twice at 45 days interval during monsoon.

Bud rot

(Phytopththora palmivora)

Affected spindle appear yellow, later changing to brown and finally the whole spindle rots.

Early removal of the infected tissue and treat the healthy tissue with Bordeaux paste. Drench the crown with 1% Bordeaux mixture as a prophylactic measure.

Anabe roga

(Gonoderma luciderm)

Small brown irregular patches appear on the stem and a brownish exudate oozes out from these patches

Provide better drainage, isolate the affected palms by trenches, drench with 0.3% captain.

Yellow leaf disease

(Mycoplasm like organisms)

Leaves become yellow, smaller, stiff and pointed, crown gets reduced, palm remains stunted with few or no nuts.

Regular manuring, ensure drainage, grow cover crops, remove the affected palms.


Ag.
Technologies
(Horticulture)