WRI India study: harvest losses of onion, soybean and sugar apple

WRI India, in collaboration with field partners including BAIF Development Research Foundation, Samunnati, and the Centre for Advanced Research and Development, has published a working paper titled "Counting the uncounted for people and climate: Post-harvest losses in onion, soybean, and custard apple in Madhya Pradesh and Maharashtra". The study analyzes losses at the stages of harvesting, sorting, transportation, storage, and processing.

The specified states account for about 82.8 percent of the country's soybean production, 56 percent of custard apple production, and 57.2 percent of onion production. Based on the analysis of production volumes in selected districts, the annual volumes of post-harvest losses were calculated: 16.89 lakh tonnes (lt) for onion, 4.16 lt for soybean, and 7,793 tonnes for custard apple. The economic value of these losses is estimated at 2,711 crore rupees for onion, 2,087 crore rupees for soybean, and 20 crore rupees for custard apple. Greenhouse gas emissions associated with the losses amount to 995,523 tCO₂e for onion, 92,206 tCO₂e for soybean, and 6,314 tCO₂e for custard apple.

In the onion supply chain (regarding the rabi harvest), farm-level storage has been identified as a critical point due to insufficient pre-drying and poor ventilation. For soybean, the key loss points are harvesting and threshing (aggravated by unseasonal rains causing moisture absorption, fungal infections, pod splitting, and the use of improperly calibrated combine harvesters), as well as gathering. For custard apple, losses occur during harvesting at farm boundaries and in cultivated orchards, as well as during field sorting and aggregation in forests and on common lands.

Lost protein for soybean amounts to 1.47 lt, which significantly exceeds the figures for onion (25,345.46 tonnes) and custard apple (126.25 tonnes). The authors of the paper emphasize that even a small reduction in soybean losses can preserve high nutritional value, making this crop a priority for intervention. At the same time, onion records high carbohydrate and energy losses during storage.

To strengthen post-harvest management, the paper highlights three priorities: improving access to appropriate technologies, infrastructure, and finance; integrating post-harvest management practices into farmer support systems; and aligning policy and market support with the stages of post-harvest handling, production, and procurement.