INTERNATIONAL PROVENANCE TRIAL OF TERMINALIA SUPERBA

Terminalia superba is a large sized, highly valuable timber tree of the semi-deciduous and closed wet forest formations of West and Central Africa.

Within the framework of the cooperative seed collection programme between the Centre Technique Forestier Tropical, France and FAO's Forestry Department, a wide collection of provenances has been obtained over the past years in several African countries through cooperation with national forestry organizations.

A total of 30 provenances (see next page) including 362 mother trees (with seed collected in most of the cases from a minimum of 10 trees in each provenance) are available, free of charge, for international provenance trials.

The proposed trials will be coordinated by CTFT in consultation with FAO's Forestry Department.

The rotation age of Terminalia superba in plantation varies from 30 to 40 years. As it is difficult to carry out adequate evaluation work over such a long period, two types of design are proposed depending on the objective of the trial:

• a design for short-term trials (5 to 7 years), where the objective is to assess the adaptability and the initial vigour of the provenances. This type of trial is recommended in countries where the species is not very well known or has never been introduced;

• a design for medium term trials (10 to 12 years), where the objective is to assess the production in terms of yield and quality of the product. According to experience, one third of the rotation age will usually give rather accurate information. At this time the trees will generally have reached 18 to 20 m in height and over 25 cm in diameter when established in adequate environment. This type of trial is recommended in countries where Terminalia superba has already shown some potential.

Further details on the recommended designs and guidance for their implementation are available, upon request, at FAO's Forestry Department to those who are interested in participating in the trials. More information on the species will be provided at the same time. This will include: (i) occurrence and main characteristics, (ii) silviculture in plantations and (iii) knowledges already available on the biology, physiology and genetics of the species.

Requests for seed, together with all necessary import permits, special instructions about compulsory pesticide treatment, etc., should be addressed to CTFT, Division matériel végétal, 45bis Avenue de la Belle Gabrielle, 94736 Nogent-sur-Marne, Cedex, FRANCE, with a copy to FAO's Forestry Department. The request should reach CTFT at least two months before the seed is required for sowing. The number of proposed trial sites and the design to be used should be clearly stated. In order to allow a selection of an appropriate range of provenances, the letter requesting the seeds should provide site details on the format shown on page 26. The sowing period should also be indicated, taking into account that the period needed for producing plantable size seedlings is about 5 months. Terminalia superba seed does not store well at ambient temperature or at high moisture level. Seed despatch should therefore be requested so that the seed is out of cold storage for the shortest time possible.

An article on T. superba by M. Corbasson and O. Souvannavong, CTFT, will be published in the next issue of FGRI.

TERMINALIA SUPERBA PROVENANCES AVAILABLE FOR INTERNATIONAL PROVENANCE TRIALS