LOCAL FRUITS - Part 6

DURIAN 3

The name durian comes from the Malay word duri (thorn) together with the suffix -an (for building a noun in Malay). D. zibethinus is the only species commercially cultivated on a large scale and available outside of its native region. Since this species is open-pollinated, it shows considerable diversity in fruit colour and odour, size of flesh and seed, and tree phenology. In the species name, zibethinus refers to the Indian civet, Viverra zibetha. There is disagreement regarding whether this name, bestowed by Linnaeus, refers to civets being so fond of the durian that the fruit was used as bait to entrap them, or to the durian smelling like the civet.

durian flowers

Durian flowers are large and feathery with copious nectar, and give off a heavy, sour and buttery odour. These features are typical of flowers pollinated by certain species of bats that eat nectar and pollen.According to research conducted in Malaysia in the 1970s, durians were pollinated almost exclusively by cave fruit bats (Eonycteris spelaea). However, a 1996 study indicated two species, D. grandiflorus and D. oblongus, were pollinated by spiderhunters (Nectariniidae) and another species, D. kutejensis, was pollinated by giant honey bees and birds as well as bats.

Over the centuries, numerous durian cultivars propagated by vegetative clones have arisen in southeast Asia. They used to be grown with mixed results from seeds of trees bearing superior quality fruit, but are now propagated by layering, marcotting, or more commonly, by grafting, including bud, veneer, wedge, whip or U-grafting onto seedlings of randomly selected rootstocks. Different cultivars can be distinguished to some extent by variations in the fruit shape, such as the shape of the spines. Durian consumers express preferences for specific cultivars, which fetch higher prices in the market.

Most cultivars have a common name and a code number starting with "D". For example, some popular clones are Kop (D99), Chanee (D123), Berserah or Green Durian or Tuan Mek Hijau (D145), Kan Yao (D158), Mon Thong (D159), Kradum Thong (Thai), and with no common name, D24 and D169. Each cultivar has a distinct taste and odour. More than 200 cultivars of D. zibethinus exist in Thailand. Mon Thong is the most commercially sought after for its thick, full-bodied creamy and mild sweet tasting flesh with relatively moderate smell emitted and smaller seeds while Chanee is the best in terms of its resistance to infection by Phytophthora palmivora.

Among all the cultivars in Thailand, five are currently in large-scale commercial cultivation: Chanee, Mon Thong, Kan Yao, Ruang, and Kradum. There are more than 100 registered cultivars in Malaysia and many superior cultivars have been identified through competitions held at the annual Malaysian Agriculture, Horticulture and Agrotourism Show. In Vietnam, the same process has been done through competitions held by the Southern Fruit Research Institute. A recently popular variety is the Cat Mountain King.

In recent times, Songpol Somsri, a Thai government scientist, crossbred more than ninety varieties of durian to create Chantaburi No. 1, a cultivar without the characteristic odour, which is awaiting final approval from the local Ministry of Agriculture. Another hybrid, Chantaburi No. 3, develops the odour about three days after the fruit is picked, which enables an odourless transport yet satisfies consumers who prefer the pungent odour.