Impact of extension and peer learning on knowledge of food quality and safety: evidence from black pepper farmers in Sri Lanka

Abstract

Food quality and safety standards have become critical as agricultural development increasingly targets high value crops and markets. These standards govern physical characteristics, purity, and contaminant levels to meet high-value market requirements. However, limited access to relevant information and post-harvest technologies constrains farmers’ ability to acquire the knowledge necessary to maintain these standards. While prior research has largely focused on staple crops, evidence on knowledge enhancement in high-value crops such as black pepper remains limited. This study examines the effect of information provision on knowledge enhancement and retention among black pepper farmers in Sri Lanka, utilising a randomised controlled trial involving 660 farmers in the Matale District. Two interventions were compared: a government extension program on quality and safety standards, and farmer-to-farmer belief and experience sharing. Knowledge was assessed immediately after the interventions and six months later to capture retention. Results indicate that the government extension program significantly increased immediate knowledge and sustained these gains over six months, demonstrating strong retention. In contrast, farmer-to-farmer experience sharing showed no immediate effect but improved knowledge over time, suggesting gradual shifts in beliefs as farmers observed peers’ practices. Heterogeneity analysis reveals that participant characteristics, including age, gender, education, occupation, and baseline postharvest knowledge, influence intervention effectiveness, highlighting the need to tailor approaches for specific subgroups. Overall, the findings emphasise the importance of structured, expert-led extension programs in strengthening farmers’ knowledge on food quality and safety standards, while supporting knowledge retention through farmer learning.