Palembang Duku Fruit: Palembang, Sumatra

Ask any sidewalk duku vendor in Jakarta and chances are they will earnestly tell you that the round yellow fruit they sell come all the way from Palembang. The truth is, however, that there is hardly a duku tree to be found in the capital of South Sumatra province.

Where does Palembang’s duku fruit come from then? Ogan Komering Ulu, Ogan Komering Ilir, Muara Enim, Musi Rawas and Lahat regencies, all in South Sumatra, none close to Palembang as Khairul Saleh explains.

The good news is that Palembang duku tastes sweeter than duku fruit from other provinces and that explains why sidewalk vendors will tell you that their duku came from Palembang.

South Sumatra has long supplied Jakarta and other big cities on Java with the fruit, the scientific name of which is lansium domesticum corr. In fact, people in Jakarta and other cities in Java often enjoy the fruit ahead of South Sumatra residents themselves. The reason is economic. At the peak of duku season, the fruit sells for Rp 1,000 (US$0.11) per kilogram in South Sumatra, compared to between Rp 6,000 and Rp 9,000 in Jakarta.

Aside from Jakarta, Palembang duku are also exported to Bandung, Surabaya and Semarang. In the 1990s, duku from Belatung and surrounding areas were exported to Singapore by a wholesaler in Cirebon, West Java. After strict sorting, the fruit was packed in standard containers and transported by air from either Palembang and Lampung. The exports lasted for seven years, but due to an unknown reason, suddenly stopped.

For the long journey to Java, duku fruits are packed in specially designed wooden boxes measuring 20 cm long, 20 cm high and 40 cm wide. A box weighs between 15 and 18 kilograms.

Come harvest time, plantation owners, village youths who serve as tree climbers and deliverers, middlemen and box makers are all engaged in the horticultural business.

According to Subrandianto, 36, a duku farmer in Belatung village, Lubuk Batang district, Ogan Komering Ulu (OKU) regency, duku trees have been handed down through generations and many are hundreds of years old.

“For us, duku trees are inherited from parents and even ancestors so their existence should be preserved,” Subrandianto said.

Dozens of villages around Belatung also produce duku, including Lubuk Batang Lama and Lubuk Batang Baru, Belimbing, Durian, Kerto Mulyo and Kepahyang. The products of these villages are known for their very sweet taste, just like those of Rasuan, now famous at Kramat Jati wholesale market in East Jakarta.

Duku trees are not so difficult to maintain and farmers spend little money on fertilizer. The generally sandy soil of plantations or the land close to Ogan River are ideal for duku because of the steady water supply and natural fertilizer formed by falling leaves.

“Monkeys, squirrels and bats are the only pests when the harvest season comes,” said Subradianto, who said he had inherited around 100 duku trees from his parents.

Theoretically, a duku tree takes at least 12 years to bear fruit. Subrandianto said it all depended on soil conditions and trace elements.

“Most duku trees (in the province) bear fruit after 15 years, some even 20 years. The long period it takes for duku trees to bear fruit has prompted us to treat duku as an auxiliary crop rather than a primary source of income,” he said.

Duku, which is round or sometimes oval, belongs to the Meliacceae family. It has smooth and thin brownish yellow skin containing sap. Its segmented flesh is translucent white and tastes sweet. The flesh constitutes between 64 and 77 percent of the fruit.

Apart from being consumed fresh after peeling, some parts of duku have other health benefits. In the season when mosquitoes transmit diseases, the fruit’s skin can be used as a repellent. Villagers in the Philippines dry duku skin in the sun and burn it to keep insects away.

The skin also serves as an anti-diarrheal drug due to its oleoresin content. Duku seeds can be used to cure fever by grinding them into fine power, as done by villagers in Malaysia. The Duku’s bark is also effective in treating dysentry and malaria. Those stung by scorpions can be cured with a duku bark power paste.

The fruit’s skin indicates the age of a duku tree. Thick-skinned duku usually come from young trees. The thicker the skin is, the younger the duku tree is. Duku trees aged over 40 bear sweeter fruits than younger trees.

With improved communications and transportation, wholesalers from different parts of South Sumatra and even Jakarta now come to duku producing regencies to buy the fruit long before the harvest time.

Wholesalers usually buy duku in three ways. The first is what they call an on-the-tree purchase. This basically means that buyers purchase duku in plantations wholesale. As the purchase agreement is made before the harvest season, often one month before the harvest time, wholesalers usually use the services of assessors to predict the yield of each tree.

Experienced assessors can estimate the quantity of a duku harvest by the size of duku tree trunk. A duku tree trunk with a diameter of a drum can produce around one ton, while those of a medium size aged over 20 years can yield 300 to 600 kilograms and aged over 60 can bear 800 and 900 kilograms.

“Experienced assessors of duku tree production capacity will not miss by much,” Subrandianto said.

The second is buying under the tree, meaning wholesalers buy duku plucked by reapers or climbers, which are weighed and paid for in cash. The reapers themselves work for plantation owners.
The last method is buying through middlemen, who collect duku and offer the fruit to villages from remote plantations. These intermediary collectors are locals, including women and children.

In the past, some wholesalers used chemicals, such as calcium carbide painted onto duku trees, to speed up the fruit’s ripening process, especially when the price is increasing. While the trick works, the practice often causes the duku tree to become barren in the next harvest season.

“They (the wholesalers) have been blacklisted and will no longer be allowed to buy duku in Belatung and the surrounding areas,” said Subradianto.

Khairul Saleh