International research on vegetable improvement in East and Southern Africa: Adoption, impact and returns
This study analyzes the adoption of tomato (Solanum lycopersicum) and African eggplant (Solanum aethiopicum) varieties developed through international agricultural research, released by national agricultural research and extension systems (NARES) and supplied to farmers by private seed companies in East and Southern Africa from 1990 to 2015. We found that 50% of tomato and 98% of African eggplant commercial seed production in the region were varieties developed by the World Vegetable Center. WorldVeg and NARES invested US$ 6.9 million in research, extension, and promotion of these two crops. This generated economic gains of US$ 254 million for tomato and US$ 5 million for African eggplant in Tanzania up to 2014. The internal rate of return is 29.3% for tomato and 12.3% for African eggplant, though we project the latter to increase to 26.0% by 2024 as adoption only started in 2007. These results indicate international research into vegetable improvement to give returns to investment that are as high as those previously reported for some staple crops.