Tag: clones
Evidence of early genetic variation in survival and growth traits of baobab (Adansonia digitata L.)—the way forward for domestication and breeding
The results of a Adansonia digitata provenance and clone trials situated in Sadore (Niger) and Samanko (Mali) indicate genetic variation at both provenance level and among clones. There were significant differences among provenances at Sadore in both survival and height by age 10. Differences in survival were very marked, and suggest that provenances ranged from very poorly- to well-adapted to the Samanko site. However, height was weakly and negatively correlated to survival; possibly the trees may have grown slightly taller because of less competition. West African provenances have a tendency towards faster growth than those of East African origin, and the provenances from drier locations tend to be better adapted. While early variation among 4 year-old clones of leaf development, an important production trait, was indicated, future observations at later ages on fruit traits will be required to make valid selection decisions. The reported 10 year-old provenance variation in tree survival and growth suggest valuable gains could be made by selection of the best provenances. Further trials across a wider range of sites, representative of target planting sites are recommended. Both genebanks contain valuable genetic plant materials worth maintaining for further research and development.
Successful grafting elite cocoa clones (Theobroma cacao L.) as a function of the age of rootstock
Côte d’Ivoire, the world’s largest cocoa producer, faces numerous challenges because the yield of orchards is low due to several factors including the non-use of improved plant materials. This work is part of ICRAF’s Vision for Change (V4C) project, which aimed at contributing to the regeneration of cocoa farms by making effective plant materials available to small cocoa producers. It essentially consisted in evaluating the effect of the age of the rootstock on the success of grafting to obtain a satisfactory quantity of improved plants in the nursery. The study was carried out in Adiopodoumé at the National Agronomic Research Center (CNRA). Ten elite cocoa clones from the “Vision for Change” project were used as scions. Top grafting was performed on seedlings of 2, 3- and 4-months used as rootstocks. The experimental design was a randomized complete block design with 3 replications. Data collection was focused on the grafting success rate and morphological parameters. The results showed that the grafting success rate is proportional to the rootstock age. Two months after grafting, the success rate was low. This indicates that grafting should eventually start at 3 months. This period could therefore represent a good stage to successfully graft and replant cocoa seedlings.