Feed the Future
This project is part of the U.S. Government's global hunger and food security initiative.

Postharvest Science: A Key Element for Achieving Food Security

This post was a finalist in Agrilinks' Young Scholars Blog Contest. Read more about the contest and the other finalists here. A huge thank you to all the young scholars who submitted blogs for this contest.

Last August I co-led a short postharvest “Training of Trainers” course in Morogoro, Tanzania alongside Dr. Steven Sargent from University of Florida (UF) and Dr. Ramadhani Majubwa from Sokoine University of Agriculture (SUA). This course is a component of a project that focuses on building capacity in postharvest management in Tanzania and is a collaboration between Kansas State University, UF, SUA, and UC Davis, led by Dr. Eleni Pliakoni of Kansas State. It is supported by the Feed the Future Innovation Lab for Horticulture. In this training we taught local extension officers and farmers a variety of topics, including basic principles of postharvest handling, proper postharvest management practices and food safety management. The trainees had the opportunity to gain hands-on experience through a series of practical activities with a variety of postharvest tools such as cooling methods, packaging and how to build and use the UC Davis Chimney Solar Dryer.

It was my first time visiting a developing country, which provided me with a firsthand account of the food security challenges these countries are experiencing, specifically in regard to postharvest handling. In developing countries, more than 40 percent of the food produced is lost at the postharvest level (FAO, 2011). Indeed, this fact can be easily corroborated with a visit to the local produce market. Piles of fruits and vegetables are exposed to the elements, and if they are not sold the same day, the majority is lost due to spoilage. The extended losses at these markets can be attributed to two main factors: improper handling and lack of basic infrastructure. Delicate produce is subjected to rough handling during harvest and transportation. Crops are typically not sorted to eliminate damaged and diseased product, and thereafter are crammed into huge sacks or baskets and transported to the market. As a result, a large portion of the product arrives at the market severely damaged. The deterioration accelerates in the marketplace where the products are piled on the ground and exposed to the sun and extreme temperatures.

During this trip, I saw the urgent need to provide local farmers with the fundamentals of postharvest handling knowledge. The application of this knowledge will benefit their businesses, and in the bigger picture, will improve public health and contribute toward local food security. At the same time, infrastructure in Tanzania is nearly non-existent. The road conditions are poor, in many areas clean water and electricity are not readily available and farmers lack the capital to invest in technologies, such as proper packing material and cooling systems. This underlines the need to invest in infrastructure and technology and provide access to capital. While these issues are mostly beyond the jurisdiction of the postharvest scientist, we can still provide the farmers with low-cost, low-tech applications which are within their reach and meet their needs. Successful examples of this concept are the UC Davis Chimney Solar Dryer and the Zero Energy Cool Chamber, which can be constructed easily by the farmers using inexpensive and readily available materials to provide considerable postharvest benefits.

This trip opened my eyes to the vast contrast between the developed and developing world. Contrary to Tanzania, in the United States more than 40 percent of the edible food is lost, or better said, wasted, at the retail and consumer level (FAO, 2011). Huge amounts of perfectly good food for consumption are wasted, especially after purchased because it is kept too long in the refrigerator or thrown away after developing minor deterioration. Moreover, a significant amount of fruits and vegetables never actually reach consumers because they are rejected as outgrades due to cosmetic concerns such as size, shape or minor blemishes. It is the role of the postharvest scientist and extension officer to contribute to changing the market philosophy, educate consumers and influence their perceptions/habits. In both the developed and developing world, postharvest science is equally relevant and of major importance. In both cases, resources are used for producing food that will either never reach the consumer or will never get consumed.

The urgent challenge that the agricultural field is facing is to continue feeding the world’s constantly growing population as resource availability steadily declines. Keeping up with the current system of high-input, unsustainable agriculture while wasting so much food is simply not a solution. Turning to sustainable production systems while minimizing the huge amounts of food loss and waste occurring in the global food system, on the contrary, is a solution.


FAO. Global Food Losses and Food Waste. Extent, Causes and Prevention. Food and Agriculture Organization of the United Nations, Rome 2011. Available at: http://www.fao.org/docrep/014/mb060e/mb060e00.pdf.