Citation
Yeang H.Y, . and Othman Hashim, . Destabilisation of lutoids in Hevea brasiliensis latex during early and late flow. pp. 45-58. ISSN 0127-7065
Abstract
Lutoid damage in latex exuding from the rubber tree has been associated with the onset of latex vessel plugging and the subsequent cessation of flow. The commonly held supposition that lutoid damage (and by inference latex vessel plugging) is most intense at the beginning of flow when the tree is tapped is re-examined. Damage to lutoids in latex collected at various intervals after tapping and just prior to flow cessation was assessed by the appearance of the bottom fraction of centrifuged latex at the bursting index of lutoids. Although increased bottom fraction damage was regularly observed in the initial latex fraction the very extensive damage has been previously been reported to occur immediately after tapping was found to be uncommon in regularly tapped trees. Lutoid damage as determined by the bursting index fell briefly after the initial flow (1st min) and was lowest between the 4th and 15th minute. But thereafter the bursting index increased steadily until cessation of flow by which time lutoid damage in the latex was most severe. Water potential was observed to increase as the latex became more dilute during the course of flow but it was not clear to what extent lutoid damage could be attributed to the resulting osmotic shock. Based on the results of this study a reassessment should be made of the common belief that the early flow latex is highly unstable and that latex is exuded during the later flow is more stable.
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Abstract
Lutoid damage in latex exuding from the rubber tree has been associated with the onset of latex vessel plugging and the subsequent cessation of flow. The commonly held supposition that lutoid damage (and by inference latex vessel plugging) is most intense at the beginning of flow when the tree is tapped is re-examined. Damage to lutoids in latex collected at various intervals after tapping and just prior to flow cessation was assessed by the appearance of the bottom fraction of centrifuged latex at the bursting index of lutoids. Although increased bottom fraction damage was regularly observed in the initial latex fraction the very extensive damage has been previously been reported to occur immediately after tapping was found to be uncommon in regularly tapped trees. Lutoid damage as determined by the bursting index fell briefly after the initial flow (1st min) and was lowest between the 4th and 15th minute. But thereafter the bursting index increased steadily until cessation of flow by which time lutoid damage in the latex was most severe. Water potential was observed to increase as the latex became more dilute during the course of flow but it was not clear to what extent lutoid damage could be attributed to the resulting osmotic shock. Based on the results of this study a reassessment should be made of the common belief that the early flow latex is highly unstable and that latex is exuded during the later flow is more stable.
Additional Metadata
Item Type: | Article |
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Additional Information: | Summary (En) |
AGROVOC Term: | HEVEA BRASILIENSIS |
AGROVOC Term: | LATEX |
AGROVOC Term: | DANOS |
AGROVOC Term: | FLUJO |
Depositing User: | Ms. Norfaezah Khomsan |
Last Modified: | 24 Apr 2025 05:51 |
URI: | http://webagris.upm.edu.my/id/eprint/17293 |
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