The Commonwealth Forestry Institute (Oxford, U.K.), in cooperation with other organizations in Latin America and Australia, has acquired wide-ranging seed collections of Cedrela and the closely related species Toona ciliata var. australis. It is proposed to distribute this seed for international provenance trials as part of CFI's continuing contribution to the FAO Global Programme for the Improved Use of Forest Genetic Resources.1
A first trial of Cedrela with a restricted range of provenances was made available in 1968. Whilst concentrating on Cedrela odorata L. this second trial will provide an opportunity to evalualuate other species in the genus such as C. fissilis Vell., C. montana Moritz ex Turcs., and in particular C. angustifolia Moc. and Sesse ex DC. The trial will also provide an opportunity to compare Cedrela with a limited number of provenances of Toona ciliata M. Roem. var. australis (F.V. Muell.) C.DC. Toona is closely related to Cedrela and has proved to be resistant to the shootborer Hypsipyla grandella Zeller in the neotropics and is an important timber tree in its own right.
Seed collection for comprehensive provenance trials of Cedrela and Toona is now virtually complete. Small experimental quantities of seed are available for distribution free of charge to researchers who wish to participate in the international programme.
Requests for seed, together with all necessary import permits, special instructions about compulsory pesticide treatment etc., should be sent to the Unit of Tropical Silviculture, Commonwealth Forestry Institute, South Parks Road, OX1 3RB Oxford (Attention: Senior Research Officer). The requests should reach the CFI at least two months before the seed is required for sowing. The number of proposed trial sites, and the number of provenances required for testing (up to 16), should be clearly stated. Brief site details of latitude, altitude, soil profile, and rainfall and temperature regimes are also useful for selecting an appropriate range of provenances.
Cedrela does not store well at ambient temperatures or at high moisture levels. Seed despatch should therefore be organised so that the seed is out of cold storage for the shortest time possible.
Many researchers have acknowledged that there is much to be gained from a programme of international cooperation and exchange of information. Consequently the CFI has developed facilities for the computerised storage and retrieval of provenance trial assessment data, which are available to all contributors of information. This pooling of data has greatly assisted the identification of growth characteristics that are persistent over a wide range of sites, thus accelerating the process of provenance evaluation, and assisting in the early implementation of conservation measures. If researchers wish to take advantage of these facilities it is desirable that a standardised experimental design is used. It is suggested that a randomised complete block design is employed with five replications, 49 (7 × 7 rows) tree plots, and a planting distance of 3 m.
For any further information please contact the CFI.
