Tapping the potential of grafting to improve the performance of vegetable cropping systems in sub-Saharan Africa. A review

Summary

Vegetable grafting is developing worldwide to cope with biotic and abiotic stresses. This technique faces strong regional disparities and its potential to improve crop performances is currently underexploited in sub-Saharan Africa. This review explores the potential of grafting to increase and secure vegetable production in challenging production conditions in sub-Saharan Africa and to identify the obstacles to its adoption. The major conclusions that can be drawn from the review are (1) the capacity of vegetable grafting to overcome several agronomic challenges commonly encountered in sub-Saharan Africa particularly for soilborne diseases; (2) grafting does not systematically lead to higher yields since the performance of grafted plants is closely linked with the combination of scion–rootstock chosen; (3) resistant rootstocks to the local soilborne pathogens could be identified through short-term laboratory and field experiments whereas the improvement of the tolerance to abiotic stresses would require deeper knowledge on underlying mechanisms; (4) the significant increase in the cost of using grafted plants are warranted in systems where there are no other technical alternatives to manage biotic and abiotic stresses, where profitability per plant is high, or where the use of grafted plants makes it possible to reach a profitable niche market such as off-season or organic products; and (5) vegetable grafting should therefore be promoted by providing evidence for its profitability in different production systems (open field and greenhouse cultivation) combined with supply-side interventions to build or strengthen the capacity of nursery operators to provide a continuous supply of good-quality grafted plants.