RESEARCH ARTICLE

Journal of Oil Palm Research Vol. 36 (2) June 2024, p. 234-245

DRY-HEAT TREATMENT FOR RELEASING THE DORMANCY OF STORED OIL PALM (Elaeis guineensis Jacq.) SEEDS

VICHAI WONGVARODOM1; ROSSUKHON SOOKKARN1; NATANONG MUANGNAPHO1; THEERA EKSOMTRAMAGE1; SAITHIP THIPPAN1 and LADAWAN LERSLERWONG1*

DOI: https://doi.org/10.21894/jopr.2023.0015
Received: 10 August 2022   Accepted: 6 February 2023   Published Online: 29 March 2023
ABSTRACT

Seed dormancy of oil palms, after harvesting with low and non-uniform germination, is a significant problem for commercial seedling production. Practically, dry-heat treatments are performed to release the dormancy. This study is aimed to investigate the optimum heating requirement to remove the Sub-PSU1 oil palm seed dormancy, after different storage times while waiting for a commercial order and breeding program before the germination occurs. Abscisic acid levels, after the heat treatment of stored seeds were also studied concurrently. It was found that the dormancy of oil palm seeds had entirely declined naturally after 15 months of storage at 20°C, with germination of 85% within 49 days. A dry heat treatment at 40°C for 45 days, being shorter than the traditional practice (60-80 days), is found influential in promoting the germination of oil palm seeds after 15 months of storage. This treatment also effectively delayed the accumulated abscisic acid in stored seeds at higher levels, with a more extended storage period. In conclusion, the specific condition of the dry heat treatment for breaking the seed dormancy during long-term storage at a low temperature (20°C), will certainly benefit commercial seedling production, when used in the breeding programmes of sub-PSU1 oil palm.

KEYWORDS:


1 Agricultural Innovation and Management Division (Plant Science),
Faculty of Natural Resources,
Prince of Songkla University,
Hat Yai, Songkhla 90110, Thailand.

* Corresponding author e-mail: ladawan.l@psu.ac.th, ladawanllw@yahoo.com