Résumé
Following the end of contract 7 ACP TA 084 between Ministry of Agriculture of Tanzania and CIRAD and the pilot project on mass propagation of selected individual hybrid trees through somatic embryogenesis, Cirad considered its duty to check the plants obtained before they are established in the field. The purpose of this mission was thus mainly to assess the survival of somatic embryos delivered to Lyamungu, and the types and proportions of variants within the plants ready to be planted. The survival rate at this stage was low (31%). We attribute it mainly to cold temperatures combined with numerous mistakes in management. However there remain enough plants for a real large-scale multilocational clone trial. The common types of variants were found but the proportions are very low (less than 1%) probably due to the high mortality rate. This mission gave us an opportunity to re-visit the mother trees of these clones. Like the rest of the station these trees have suffered a total lack of attention, and no additional data was made available to us. The identification of these trees is not clear. CBD tolerance as assessed in Cirad lab is variable and high in some cases. More trees should be used for clonal propagation. The envisaged dispatch of plants to both small, middle size and large farmers is good provided each clone is clearly identified so that a feedback from the users allows refining the choice of clones. The main goal for the immediate future should be to lower the costs by improving the acclimatisation and nursery conditions (higher temperatures and greater commitment). Also, the release of this planting material to a larger number of coffee growers will need to be accompanied by a greater concern of research regarding not only environmental, but also socio-economic conditions in which the crop is grown. A proposal by Cirad for further co-operation may be considered when TACRI defines its strategic plan for the coming years. (Résumé d'auteur)