The jackfruit (Artocarpus heterophyllus) is a common village tree cultivated throughout Malaysia. Fruits are available almost throughout the year though the peaks are around June and December. They are a valuable source of carbohydrates with a lesser amount of calcium and phosphate. The pulp of the ripe fruit is eaten fresh or in syrup (preserved). Preserved or canned jackfruit has become increasingly popular, but the production is limited. Burkill described the juicy flesh around the seed as "The taste is mawkishly sweet and mousy, agreeable to natives of the East, but not to Europeans". The flavour is of ethyl butyrate. The Malays and Chinese in Malacca candy the fruit. Unripe fruits are used as a vegetable (masak lemak) or in soups and are also pickled. The large seeds are boiled or roasted and have a chestnut flavour. The seeds can also be ground into flour.
Jackfruit can be found in all states in Peninsular Malaysia. The total area under jackfruits in 1976 was about 746.20 hectares. It is grown together with other fruit trees. Until now, it has not been planted on a large scale, apart from those grown for trials by the Department of Agriculture in Trengganu. About 33% of the jackfruit in Malaysia is found in Trengganu. Other important states producing jackfruit are Kedah, Perak, Johor and Pahang. These five states constitute about 77% of the area under jackfruit in Malaysia.
As the jackfruit has been traditionally propagated from seeds, there is a wide variation in productivity and in fruit size, shape and quality, as well as in the fruiting season. Two main types are recognised (1) "Nangka Belulang" with firm flesh and (2) "Nangka Bubur" with soft flesh.
A few cultivars are known or exploited in Malaysia. A greater research effort is needed to catalogue existing cultivars and to build up stocks of desirable clonal material.
The jackfruit variety under observation is the cultivar Negeri Sembilan Satu. NS 1 is the cultivar selected for processing and it is hoped that with further husbandry improvements, the acreage of jackfruit in Malaysia will expand to meet the development of the fruit processing industry.
SOIL AND CLIMATE
Although the jackfruit is essentially a tree of the tropical lowlands, it is adapted to a wider range of conditions. It can tolerate higher altitudes and cold better than the breadfruit.
The jackfruit can be grown on a variety of soils as long as they are well-drained, but does best in deep alluvial soils of open texture. Most of the trees grown in Trengganu and Pahang are on the Holyrood series.
The most common and simplest method of raising jackfruit trees is from seeds, though other methods are also known in Malaysia. The trees do not generally breed true from seeds, so the practice has led to immense variation in yields, fruit characters and quality. Inarching and grafting by the Forkert Method is known in Malaysia as a means of perpetuating desirable clonal stocks.
The place chosen for the planting should be first cleared from old tree stumps and old roots to avoid termites and root disease. When necessary, the soil should be ploughed first, then rows are made to mark the planting intervals. Usually, jackfruits are planted at a distance of 30 ft. x 30 ft. In an acre, 48 trees can be planted. In a new area the planting interval can be reduced to 25 ft. x 25 ft., and 69 trees can be planted in an acre.
Planting holes of 2 ft x 2 ft x 2 ft., should be prepared, and top soil with 4 oz. CIRP should be added into each hole. For not every fertile soils, it is advisable to add 40 lbs. of cowdung to the top soil. Usually the planting holes are left open for fourteen (14) days before they are filled up again, and only then is the budgrafted jackfruit tree planted. It is important to remember that during planting, the bud patch is not to be covered with soil. It would otherwise cause the bud patch to rot and die. The amount of sunlight can be reduced by using shade from coconut fronds. Usually, bud-grafted trees are planted during the rainy season so that they do not have to be watered. Since watering is quite a problem in large scale cultivation, planting should be done when there is rain in order to make sure that tne plants can grow well. This is important to prevent the plants from being stunted. Shading from the coconut fronds can be removed after two weeks if the weather is fine. Otherwise, it should be left for another week or more.
For sandy soil and clay soil or the Holyrood series, legumes are required as cover crops. Calopogonium, Centrosema and Pueraria in a ratio of 5:4:1 are usually used. Cover crops are required to prevent weeds from growing, to alter the condition and fertility of the soil and also to prevent the soil from becoming too hot especially in bris areas.
FERTILIZER AND MANURING
A consistent, well-balanced manurial programme is important so as to stimulate rapid growth in young trees and to ensure maximum yield when the plants come into bearing. As nitrogen, phosphate and potash play a vital role in the plant metabolism, and markedly affect fruit production, a balanced supply of these nutrients in the fertilizer mixture must be applied to the plant.
The amount and time of fertilizer application are as shown below:
|Amount per tree/|
|Time of application|
|1st year||G||4 oz||every 3 months|
|2nd year||G||6 oz||every 3 months|
|3rd year||F||1 lb.||every 4 months|
|4th year||F||2 lb.||every 4 months|
|5th year||F||3 lb.||every 6 months|
|6th year||F||5 lb.||every 6 months|
|7th year onwards||F||6-7 lb.||every 6 months|
G = Growth mixture
F = Flowering mixture
PESTS AND DISEASES
Jackfruit is seldom attacked by serious fungal or virus diseases. The common diseases which occur are physiological, where the trees wilt and the shoots die. This is usually caused by shortage of water, flooded or waterlogged conditions. Another disease which can reduce the production of jackfruit is caused by fungal attack during the development of the fruits. This disease can be controlled by wrapping the fruits before they are attacked by fruit borers, by removing and burning the rotten flowers and fruits and also by spraying with fungicide such as Perenox, Vitigran blue twice a week during the early fruiting season.
Natural fruit drop has also been observed. Many fruit buds which are still small drop even though they are not attacked by insects or fungus. It is believed that this is due to some physiological reasons such as lack of nutrients.
A few diseases caused by insects and pests such as jackfruit borer, fruit flies, civet cat and wild boar have been reported.
Margaronia sp. is a type of Lepidopteran which can destroy every part of a jackfruit tree. They usually lay eggs on leaves and fruits. The larvae eat the leaves at the beginning and later bore into fruits and develop. After destroying part of the fruit they begin to bore into the branches and stem.
The method of controlling Margaronia larvae is to spray insecticides such as carbaryl and gamma BHC at least once a fortnight at a concentration of 0.1% of the active ingredient. For the plants which have already been attacked, it is necessary to collect and destroy the rotten fruits; the dead branches or stems have to be cut. The holes in the fresh part should be filled with paradichloro-benzene or other insecticides such as gamma BHC.
Two types of fruit flies, Dacus umbrosus and Dacus dorsata can affect the jackfruit production. Fruit flies breed in the matured fruit; the adult female lays eggs at the inner part of the skin and the larvae eat and thrive inside the fruit which later becomes rotten.
The method of controlling fruit flies is by destroying the rotten fruits, either by burning or burying them in the soil. Covering fruits using coconut leaf bags, gunny sacks or papers is good and effective.
A new method of controlling fruit flies is to use poisoned attractants such as methyl eugenol and protein hydrolysate mixed with trichlorphon (Dipterex) but the method does not give satisfactory control.
Jackfruit fruits are loved by wild animals such as the civet cat. Another pest which can cause destruction and loss is the wild boar. All immature and mature fruits at the lower part of the trees will be destroyed by these pests. Besides that, they like to dig the roots to find insects and this may cause the trees to fall.
A method of controlling them is by elimination by shooting or by using poisonous bait such as 'methomyl' (Lannate) inside pineapple or sweet potatoes.
YIELD, PRODUCTION AND PROCESSING
There is no reliable yield data on jackfruit found in Peninsular Malaysia. Data gathered by the Department of Agriculture in Trengganu showed that a jackfruit tree variety NS 1 produced 10-20 fruits/tree/season. If 15 fruit/ tree/season is an average yield per season, the yield per tree per year is therefore 30 fruits. However, data recorded in MARDI was 16 fruits/tree/year during 1978 for trees grown in Serdang for the same variety i.e. NS 1 (Musa Baba, Pers. Comn.). If 50 plants are planted in an acre, 800 fruits per acre per year will be produced. The average fruit weight recorded was 5.72 kg (12.58 lbs.). If the market price of a fruit is 10 cents per pound, then the average price of a fruit is $1.25 cents and the total production per acre per year is about $1000.
At present, the jackfruit variety NS 1 is found to be suitable for preservation and canning. Using this method, the flesh can be stored long without any loss in quality. Thus, there is no problem in marketing and it can be one of the fruits which has a great potential for the canning industry.
Processing of jackfruit has been carried out by the Food Technology Division of Serdang since 1969 and it is being continued by the Agricultural Product Utilization Division MARDI at Kuala Trengganu. The flesh is mixed with a syrup mixture, citric acid and calcium chloride during processing.
Only about 13% of the fruit can be canned. A fruit weighing 7 lb. can produce 3 - 4 tins weighing 15 oz/tin. At present, the processing cost for one tin of jackfruit is $1.00, with the cost of $0.25 for 10-11 pitted pulps weighing 200 gm.
Canned jackfruit is popular in Malaysia but its production is limited. However, it can be a potential industry in future.
ALLEN, B.M. 1975 Common Malaysian Fruits. Longman Malaysia Sdn. Bhd. Kuala Lumpur.
BURKHILL, I.H. 1966. A Dictionary of the Economic Product of Malay Peninsular. Vol. I, pp. 255-258. Ministry of Agriculture and Co-operatives, Kuala Lumpur.
GARNER, R.J. and Saeed Ahmed Chaudhri. 1976. The propagation of tropical fruit trees. Commonwealth Agricultural Beraux. Horticultural Review No.4.
LEE, C.S. (9n.d.). A guide to fruit tree establishment, Risalah Terbitan Cawangan Perkembangan. Jabatan Pertanian, Kuala Lumpur.
OSMAN MOHD NOOR. 1978. Tanaman Nangka, Risalah Perkembangan Bil. 12. Jabatan Pertanian, Kuala Lumpur.
PURSEGLOVE J.W. 1977. Tropical Crops (Dicotyledons) Longman Group Ltd. London.
DATE: February 1984
* * * * * * * * * * * * *