The Agriculture–Nutrition–Income Nexus in Tonga: Is Postharvest Loss Undermining Horticulture Market Efficiency in Tonga?

The Kingdom of Tonga has one of the highest rates of diet-related non-communicable diseases (NCDs) in the world. Initiatives to promote pro-health dietary behaviour are possibly being compromised by poor or inconsistent consumer accessibility to affordable and safe fresh fruits and vegetables, referred to as the agriculture–nutrition–income nexus. While donors increasingly focus on nutrition-sensitive agriculture across the Pacific, there is little contemporary information concerning Tonga’s domestic horticultural distribution and market system, particularly in regards to food loss. This study surveyed 292 municipal and road-side vendors on Tongatapu and ‘Utu Vava’u Islands, with the aim of mapping and analyzing horticultural markets and farm supply, transport logistics, and quantifying postharvest practice and market loss. Tonga’s domestic horticultural market structure consists of a central municipal market and on Tongatapu Island, a supplementary network of urban and rural based road-side vendors. There is limited inter-island trade, with most farms located within 25 km of the central municipal market. Mean postharvest horticultural loss was very low, at 1.4% to 5.3%, with road-side vendors more vulnerable to loss. This level of loss was thought to reflect short intra-island transport distance, the type of crops being traded, and rapid market throughput, rather than a level of value chain efficiency. Vendors regulated market supply volume and price discounting and were the principal strategies to mitigate postharvest loss. While low levels of postharvest loss, short transport logistics, and fast market throughput are consistent with a relatively efficient horticulture market system, vendor practice may be impeding fresh fruit and vegetable accessibility.