Tomato is a major source of income for smallholder farmers in sub-Saharan Africa but faces numerous constraints, including droughts, heats, and low soil fertility.
So far most commercial tomato varieties used in sub-Saharan Africa do not have a satisfactory tolerance to abiotic stresses. However, grafting a elite commercial cultivars (scion) onto vigorous genotypes (rootstock) is another means to provide tolerance. Today worldwide, grafting has been used as a proven alternative crop management strategy to increase tolerance when suitable tomato rootstocks are available. Several rootstock genotypes suitable for sub-Saharan Africa conditions hold great promise for tolerance to abiotic stresses as mentioned before. Moreover, grafting is not used in this region. The unfamiliarity with grafting techniques, tomato seed systems in sub-Saharan Africa are largely informal, and farmers practice direct sowing or grow their own seedlings for transplanting. Therefore, seedlings need to be grown in nurseries since they of much better sanitary quality, and allow for small-scale business development as they can be produced by local farmer groups.
We hypothesize that the adoption of tomato grafting technology into sub-Saharan Africa will enable smallholder tomato farmers to increase yields and income by increasing crop resilience to abiotic (drought, low soil fertility, and heat), allowing expansion of tomato production in the off season and into areas where abiotic stress limit tomato production. Thus, the present project proposes to (i) identify tomato grafting combination to overcome key production constraints in Tanzania, (ii) measure impacts of grafting on stem xylem hydraulic conductivity and water and fertilizers requirements, (iii) evaluate the profitability of grafted plants for producers and seedling nurseries (iv) train trainers and nursery operators on grafting.