Gums, resins and latexes are a most widely used and traded category of non-wood forest products. The uses of gums embrace food, pharmaceutical and miscellaneous technical applications. Resins have an equally diverse range of applications including their use in paints, varnishes and lacquers, and flavours and fragrances. Latexes are used in specialised applications such as insulating materials and in the manufacture of golf balls and chewing gum. There has been a decline in their use due to competition from synthetic products. This document contains a review of the production, markets and developmental potential of a number of gums, resins and latexes.

Gums, resins and latexes of plant origin

Pollination biology and breeding system of Acacia senegal

Acacia nilotica is truly multipurpose nitrogen fixing leguminous tree in India commonly called as babul and is a source of Indian gum arabic. It is a complex species with nine subspecies, of which six are native to the African tropics and three others are native to the Indian subcontinent. It is considered as a very important economic plant since early times as a source of tannins, gums, timber, fuel, fodder and medicine. Gum is widely used as industrial, food and medicinal purposes. This article briefly reviews the botany, distribution, ecology and environment, improved techniques of gum extraction, its uses and properties. This is an attempt to compile and document information on different aspect of Acacia nilotica and its potential uses.

Acacia nilotica :A Multipurpose Tree and Source of Indian Gum Arabic

Gum arabic production from Acacia senegal is lower in sub-humid areas than arid areas. Water stress is thought to be the reason for higher yields in arid areas. The application of ethephon is thought to mimic the effect of water stress in other plants. The objective of this study was to determine if the application of ethephon would increase the gum yields of Acacia senegal under sub-humid conditions in Cameroon. Trees receiving 40 or 120 mg ethephon were compared to controls in field experiments at a semi-arid and a sub-humid location in Northern Cameroon, over two seasons. Two provenances from drier areas (Sudan) were compared to the local one. In the first season, gum yield of the local provenance treated with ethephon was increased by 400–600 % compared to the untreated trees. Gum yield at the semi-arid location was 77, 313 and 214 g/tree with 0, 40 and 120 mg ethephon/tree, respectively, while at the sub-humid location, it was 30, 186 and 114 g/tree with 0, 40 and 120 mg ethephon/tree. However, in the second season, the effect of ethephon was not significant in the semi-arid area, whereas it was evident in the sub-humid area (up to 478 g/tree). Moreover, ethephon did not affect gum yield of provenances from drier areas (Sudan). This showed that the water-stress hypothesis has to be refined. The development of ethephon-based tapping systems is promising, but requires further studies with a wider range of environmental conditions and A. senegal provenances.

Ethephon: a tool to boost gum arabic production from Acacia senegal and to enhance gummosis processes

The development of forest-based sawmilling and ply milling industries (1980s-1990s) and pulp and paper industries (mid 1990s) plays an important role in forest resource management. Wood supply from plantation forests will have to provide an increasingly larger share of the supply in the near future, particularly of pulp logs. Technology and marketing problems are emerging in processing logs from those plantations. The development of industrial forest plantations is focused on meeting the need of pulp and paper industries’ raw material, and therefore tree species are dominated by fast growing species such as Acacia spp. and Eucalyptus spp. Government policy established more forest-based industries to promote forest based and timber processing industries in the country. Indonesia’s forest-based industry comprises a mix of non-panel forest-based industry of 81 pulp and paper mills (12 integrated pulp and paper mills; 66 paper mills; 3 pulp mills), and panel-based industry of 4,400 sawmills, 120 plywood mills, 39 block board mills, 13 chip mills, 2 Medium Density Fibre mills. The rapidly expanded Indonesian forest-based industries were not well supported by the long-term sustainable supply of raw materials. The forest-base has been supplied by an abundance of quality raw material with relatively low production costs. There were minor efforts to increase efficiency and competitiveness. There is an imbalance between log supply and demand. The technological aspects of the forest-based industry are also neglected. Observations are that most of industries were built in the 1980s and the technology is now inefficient and thus competitiveness in the global market is low. Machinery is out of date and can process higher grades and larger log sizes, but not wood wastage and smaller diameter logs. The sustainability of Indonesian pulp and non-pulp plantation forests and processing industries should be clearly planned and implemented. This paper provides a national review of Indonesian plantation forests, their processing industries’ restructuring and potential markets.

https://www.fs.fed.us/pnw/pubs/pnw_gtr604.pdf

Sustainable production of wood and non-wood forest products: Proceedings of IUFRO Division 5 Research Groups 5.11 and 5.12, Rotorua, New Zealand, March 11–15, 2003.

J. R. Bhatt

Papers

Ethephon-induced gum production in Acacia senegal and its potential value in the semi-arid regions of India.