interferes with its natural regeneration and is thus is not sustainable. Therefore, conservation and domestication of this tree should be taken seriously. Demand for East African sandalwood has been fuelled by a search for an alternative to the diminishing resource of the Indian sandalwood. Since the Sultan of Mysore declared it a royal tree in 1792, Indian sandalwood (Santalum album) resources have dwindled and the prices skyrocketed. Trade has now shifted to Australian and East African sandalwood. In 2006, the Kenya Forestry Research Institute (KEFRI) embarked on research on domestication and cultivation of the East African sandalwood. Tremendous success in the propagation of sandalwood has been recorded ever since, in spite of various constraints faced due to lack of understanding of its silvicultural requirements. See d germination was found to be low and highly variable between individual trees and at times could take up to six months. Sandalwoods grow slowly and develop a core of heartwood gradually. This only accelerates when trees are about 20 years old. Research at KEFRI has generated knowledge that will support propagation, cultivation and commercialisation of East African sandalwood.
A useful parasite
The East African sandalwood has potential as a cash crop By J. Machua, B. Kamondo, Linus Mwangi, G. Giathi and O. Chahilu
T
he East African sandalwood, scientifically known as Osyris lanceolata is a shrub or a small tree growing to a height of six metres. The tree is known by various local names; msandali (Swahili) muthithii (Kikuyu), mberegesa (Chagga), olseyeayyesi (Maasai) and kithawa (Kamba) among others. It exists dioeciously (different male and female plants) and is indigenous to the East and South African region. The tree occurs on rocky ridges, mountain slopes and the margins of dry forests and in evergreen bushland, in grassland and in thickets. The tree grows at an altitude of between 900 - 2550m above sea level. Osyris belongs to the semi-parasitic plant family Santalaceae (the sandalwood family) and its roots will always be found associating with those of host plants.
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The East African sandalwood is among the sandalwoods known for producing fragrance-scented wood and a world famous essential oil used in various cosmetics and fragrance industries and has gained popularity in medicine. Traditionally, the tree has different uses among different peoples in Kenya, including making of red dye, smoking milk containers, healing wounds and treating stomachache, tonsils, diarrhoea, ulcers, snakebite and rashes. The demand for sandalwood has by far outstripped its supply. Sandalwood is harvested in the wild by uprooting the whole tree including its roots because the essential oil concentration is higher in the roots than the trunk. Although the available sandalwood resource base is not yet known, much of the harvested material in Kenya is smuggled out of gazetted forests, game parks and nature reserves. This mode of exploitation seriously
Propagation of East African sandalwood Propagation of sandalwood from seeds yielded varying results, with seeds from some regions of Kenya recording a germination rate as low as 4 per cent while for others it was as high as 80 per cent. Many seeds had succumbed to insect attacks or abortive embryo formation, resulting in empty fruits. Propagation from cuttings was hindered by a severe endogenous fungal attack whereas propagation by air layering resulted in 60 per cent success.
Nursery establishment Sandalwoods are semi-parasites and were first reported by J. Scott in 1871 in the Journal of Royal Horticultural Society of India. It has been observed that the absence of root hairs and the presence of actively absorbing haustoria on the roots of sandal plants is evidence that sandal plants depend on hosts for certain nutrients. It is estimated that sandal plants can be parasites on over 300 species of plants, ranging from grasses to other sandal plants. Sandalwoods show different growth patterns on different host species.
Miti July-September 2009