RESEARCH ARTICLE

Journal of Oil Palm Research Vol. 11 No. 2, December 1999, p. 98-113

THE OIL PALM TRUNK AS A CARBOHYDRATE RESERVE

HENSON, I E*; CHANG, K C**; SITI NOR AISHAH, M**; CHAI, S H**; HASNUDDIN MHD, Y*; ZAKARIA, A**

ABSTRACT

Samples of oil palm trunk tissues were analysed for their contents of soluble sugar (SS), starch and acid-hydrolysable polysaccharides (PS). Starch was found in high concentrations only in samples taken near to the trunk apex of young palms, while SS and PS were present in appreciable amounts throughout the trunk.

The total amounts of carbohydrates present in the trunk of an eight-year-old palm were calculated as being sufficient to sustain the production of up to 38 kg of FFB.

Chromatographic and enzymatic analysis of the carbohydrates showed that sucrose was the main form of SS, followed in descending order by glucose and fructose. Acid hydrolysis of the polysaccharide fraction released mainly glucose together with appreciable proportions of a material with the chromatographic properties of xylose, together with some fructose.

Three trials were conducted to monitor variation in trunk carbohydrates in relation to bunch load, genotype and time of year. In the first trial, trunk carbohydrates levels were  compared in selected low and high yielding tenera palms. High yielding palms had higher SS levels, lower PS levels and a higher proportion of carbohydrate in the form of SS (%S) than low yielding ones. In the second trial, trunk carbohydrate were measured in 20 mature commercial teneras over a period of more than two years. Mean PS levels were again negatively correlated with bunch yield while %S was positively correlated with yield. The third trial made use of infertile pisiferas, and tenera sibling  progenies from the breeding population. Tenera palms had lower PS levels and more of the trunk carbohydrates present in the form of SS than did pisiferas. Infertile pisiferas had higher PS levels and a lower proportion of SS than did fertile pisiferas.

The results are discussed in relation to the possible role of trunk carbohydrates as a source of assimilates during periods of peak bunch production.

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* 21 Hurrell Road,
Cambridge CB4 3RQ, UK.

** Palm Oil Research Institute of Malaysia,
P.O. Box 10620,
50720 Kuala Lumpur, Malaysia.