Developing strategies to alleviate heat stress-induced flower abortion and prevent yield losses in fine and runner beans for commercial growers and for small-holder farmers in Kenya.

Climate models predict that yields of major crops in Africa will decline by up to 8% by 2020 and 10-20% by 2050. Higher temperatures, exacerbated by decreasing water availability for irrigation, will become the primary threat to fine and runner bean production. New varieties and improved growing practices that increase resilience to combined stresses are needed. Vegpro (Kenya) Ltd (VP) are a major exporter of fine and runner beans, grown both on commercial farms that employ 8,000 local workers, and on 5,000 outgrower sites across Kenya. In hot dry months (Jan-March, July-Sept), a combination of heat and drought stress can reduce yields by 20-30%, and since current mitigation strategies are inconsistent and ineffective, overall losses can reach 50-60% due to a failure to meet commercial product specifications. Lost revenue to VP is estimated at £8.6M p.a., and for VP's 5,000 outgrowers, losses of 33% of annual income are commonplace. We will develop innovative practical solutions that improve plant productivity by 20% and reduce waste by 40% under combined heat and drought stress, generating additional income for the consortium and VP’s outgrowers of £6.6M p.a.. Project outputs will accelerate sustainable intensification on large- and small-holder farms in a changing climate, increasing local food and job security, and improving well-being and social harmony.