A few years after the world food price crisis of 2007-2008, a report by the UN Food and Agriculture Organization (FAO) estimated that the world lost or wasted one-third of its food supply every year. Since then, this has become a prominent issue on the development agenda; reducing food loss and waste could potentially increase food availability for the poor and reduce the environmental footprint of agriculture.
Yet one of the key challenges in trying to reduce food loss and waste is to define it and measure it. One type of food loss that has received significant attention is post-harvest loss, due to its potentially adverse effects on farmer incomes, but also on traders and retailers. Recent measurements of post-harvest losses using higher quality surveys, such as those conducted by researchers from the CGIAR Research Program on Policies, Institutions, and Markets, are summarized in a forthcoming book by Alan de Brauw and Erwin Bulte. They show that in Africa, losses for non-perishable crops typically range between 1.3 and 7.3 percent. Therefore at least in Africa, remedies for post-harvest losses must be cheap to be adopted, and will not necessarily lead to large increases in food availability.
By contrast, there is very little evidence about perishable crops. To begin to fill this gap in our knowledge, a recent survey in Kenya, conducted as part of the Voices for Change partnership and co-financed by A4NH, measured post-harvest losses in the tomato value chain in Laikipia County of Kenya. Tomatoes are highly vulnerable to post-harvest losses due to their softness, perishability, and susceptibility to pests. Most farmers and intermediaries surveyed were men, 89 and 80 percent, respectively, while most retailers, 74 percent, were women. The median farmer cultivated one acre of tomatoes and produced 1.2 metric tons of tomatoes (valued around US$700) and sold them in multiple transactions (91 percent).
The survey found that post-harvest losses, calculated as a percentage of the original value, were relatively high, at around 28 percent. This value was calculated using a series of weighted averages from each stage of the value chain. Farmers experienced the largest losses, an average 16.4 percent or US$114 of the initial value of their tomatoes, which is a significant financial loss for rural households. Farmers reported their losses were mostly the result of mechanical damage and spoilage. Since tomato farmers typically outsource transportation needs to intermediaries or retailers and do not usually store their tomatoes, their losses at other post-harvest stages were very small (1.7 percent). Most intermediaries do not store or repackage tomatoes, so losses during those stages were also minimal, at 2.1 percent of the initial value, more than half of which, or 1.3 percent of the initial value, occurred during transport from farm-gate. Whether low intermediary losses are due to profit incentives or short turnarounds between purchase and resale warrants further investigation.
Retailers experienced the second greatest losses, at 12.5 percent of initial value. Approximately two-thirds of this, or 8.6 percent of the initial value, occurred during storage. The next most significant stage of retailer loss was during transport from the farm. These losses, which represented 3.8 percent of the overall initial value, were reported by 90 percent of retailers who purchased directly from farmers (43 percent), and amounted to as much as a third of initial value.
Mitigating losses of higher-value, perishable crops like tomatoes could have significant and positive effects on farmer incomes and decrease the need to cultivate additional land. Based on 2016 production estimates in Laikipia County, the 28 percent loss in value estimated by this study represents a collective US$2.74 million to stakeholders along the value chain. Meeting the Sustainable Development Goal of reducing food loss and waste by 50 percent would mean value chain participants would gain on the order of US$1.37 million collectively in Laikipia County alone. And while perishable crops may not provide as many calories as staple grains and cereals, they are crucial sources of micronutrients. Increasing the supply of perishable fruits and vegetables could reduce prices for households currently unable to afford healthy, balanced diets.
The project researchers summarized four main policy recommendations to reduce post-harvest losses in the tomato value chain:
After nearly a decade of increased research and attention on food losses and waste, there are but a handful of quantitative survey-based studies on post-harvest losses for perishable foods. Using the FAO Food Loss and Food Waste Database and including studies since, we identified less than 10 quantitative-survey based estimates in the last ten years. Additional research on different commodities in different contexts is needed to understand whether losses are consistently high, why such significant losses are occurring, what policy mechanisms can be leveraged to mitigate these losses, and how can this be done cost-effectively for smallholders.
As we set the agenda for the next decade of research on food system transformation, including food losses and waste, it is worth asking if perishable crops deserve more of our attention. Perhaps it is time to shift the agenda on post-harvest losses; it certainly is more than a few rotten tomatoes.
Laura Leavens is a Research Analyst in the Markets, Trade, and Institutions Division of the International Food Policy Research Institute.
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