Dipterocarpus alatus known colloquially as the resin tree, is a tropical forest tree, of dense evergreen or mixed dense forests, in tropical Asia. It is considered vulnerable. It often occurs gregariously along river banks and is a key planting species for regenerating deforested land around the Dong Nai river and Cat Tien National Park.
Cultivation details
A plant of the lowland tropics where it is found at elevations up to 500 meters. It grows best in areas where annual daytime temperatures are within the range of 22 – 32°c, though it can tolerate 10 – 36°c. It can be killed at temperatures of 5°c. According to one report, it prefers a mean annual rainfall of 1,100 – 2,200mm, uniformly spread through the year. Another report says it has a preferred rainfall of 3,500 – 4,500mm but can tolerate 3,000 – 5,200mm. The plant, especially when young, is very tolerant to shade and seedlings can survive under heavy shade for years. As trees grow older, they become more light-demanding. Found mainly on alluvial soils in the wild. Prefers a pH in the range 5 – 6.5, tolerating 4.5 – 7. Members of this genus generally only regenerate naturally in the shade of the forest. Seedlings and saplings can persist in dense forest shade for many years. In their first 2 years, the young plants cannot tolerate major openings in the canopy, but after they are well established (about 120cm tall) the canopy can be opened up around them to speed up their growth. The annual production of oleoresin per tapped tree is between 23 and 31 liters. Trees have thin bark and are very sensitive to damage by fire.
Propagation
Seed – it has a short viability and so should be sown as soon as it is ripe. No pre-treatment is required. Sow the seeds in a nursery seedbed, germination usually commences within 4 – 7 days at 25°c. Seedlings are ready to plant out when they are 30cm tall, which takes about 8 – 12 months. Seed storage behavior is intermediate, the lowest safe moisture content is 17%, no seeds survive further desiccation to 8% moisture content. At 12% moisture content, only 36% germination occurred after 939 days of hermetic storage at -18°c compared to 80% viability before storage. Cuttings are taken from coppice shoots produced after hedging rooted successfully with 44.5% rooting, indicating the potential for mass production of rooted cuttings from hedge orchards.