Grow against the flow: The impact of off-season vegetable production in Cambodia.

Vegetable production is strongly seasonal, creating income volatility for smallholder farmers and occasionally high prices for consumers. The ability to produce vegetables outside their regular growing season can enhance farmers' incomes and income stability, yet empirical evidence remains limited. This study evaluates the impact of training farmers in Cambodia on off-season production technologies for yardlong beans, tomatoes, and brassicas during the hot-dry and wet seasons. Using survey data collected from 172 intervention and 179 control farmers two and three years after the training began, average treatment effects were estimated by using propensity score matching and inverse probability weighting. Trained farmers adopted an average of 3-4 more off-season technologies than the control group (p < 0.01). Two years after the intervention began, the share of trained farmers producing yardlong beans increased by 12 percentage points in the hot-dry season (with average production gains exceeding 100 kg) and by 46 percentage points in the wet season (with an average increase of about 700 kg). Corresponding revenue gains were approximately USD 50 and USD 300 per farmer, respectively (p < 0.01). Three years after the intervention began, revenue gains were lower, but still significant. Positive effects on tomato and brassica production and income were observed in the wet season, but not in the hot-dry season. These findings underscore the potential of off-season vegetable production to enhance rural livelihoods and improve year-round vegetable availability. The results provide evidence for stakeholders in Cambodia and comparable lower-income countries in Southeast Asia seeking to scale up off-season vegetable programs.