Neem decline in West Africa
Throughout the semi-arid regions of West Africa the neem tree (Azadirachta indica) is used wifely for planting in shelterbelts and windbreaks to halt or reduce soil losses. The hardiness and versatility of the neem has enabled the tree to play an important part in the process of stabilizing marginal lands which otherwise would have become agriculturally derelict, whilst the tree itself provides a valuable source of timber fuel and cattle fodder as well as some highly unusual natural pesticides mainly from the seeds, (see Spore 33 page 13). The bark contains anti-malarial compounds and people are regularly seen cleaning their teeth with neem twigs. The neem tree is not native to West Africa: it was introduced over half a century ago from India. Countries such as Nigeria have planted neem extensively and it has become the most frequently used species in forestry and agroforestry projects. However, m 1990 signs of a decline in neem were noted in the Majjia Valley windbreak project of central Niger, where 15% of mature trees are now affected. A similar decline was later confirmed in north Benin, Burkina Faso, Chad, Mali and Nigeria. The condition was first observed on newly-pollarded trees, the young shoots of which are particularly susceptible. Symptoms appear first on the leaves, which become dull green, yellow or red. New leaves are crinkled, and old leaves fall early. Yellow or white gum may exude from the tips of the shoots. The shoot tips are the first to die, but eventually the whole tree is killed. The primary causal agent has not yet been identified. The genetic base of the neem tree in West Africa is thought to be very narrow indeed, although no provenance studies have been carried out in the region. A provenance study of the species in West Africa is now urgently needed so that the use of any material found to be particularly susceptible can be avoided in new plantings. Anyone with information about this condition is asked to contact: Dr Eric Boa, Tree Crops Pathologist NRI, Central Avenue, Chatham Maritime Kent ME4 4TB, UK In order to promote neem improvement the Forestry/ Fuelwood Research and Development Project (F/FRED) and the Centre Technique Forestier Tropical (CTFT) in France have recently signed an agreement to develop a workplan for a neem network. Activities are likely to include seed collection and germplasm exchange, variability studies and the establishment of progeny trials. Further details of the network can be obtained from: Dr R J Van Den Beldt Multipurpose Tree Species Research Network Secretariat F/FRED Project PO Box 1038, Kasetsat PO Bangkok 10903. THAILAND
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| Format: | News Item biblioteca |
| Language: | English |
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Technical Centre for Agricultural and Rural Cooperation
1992
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| Online Access: | https://hdl.handle.net/10568/45841 http://collections.infocollections.org/ukedu/en/d/Jcta41e/ |
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