Davis, Calif., (July 27, 2017) – Planted in a corner of the UC Davis campus is a display of technologies and vegetable crops that researchers with the Horticulture Innovation Lab have been using with farmers in Africa, Asia and Central America. Led by UC ANR’s Elizabeth Mitcham in the UC Davis Department of Plant Sciences, this program harnesses the agricultural expertise of a network of U.S. university researchers to improve how farmers in developing countries grow fruits and vegetables.
More often than not, the learning goes both ways: Adapting solutions for farmers on another continent can spark ideas that might be useful back home too.
So while the Horticulture Innovation Lab’s Demonstration Center was built to showcase international work to campus visitors, you wouldn’t be the first to wonder, “Would this technology work on a California farm too?”
Recently a team from UC Cooperative Extension in Fresno County — led by Ruth Dahlquist-Willard, UC Cooperative Extension advisor for small farms in Fresno and Tulare counties — worked with the Horticulture Innovation Lab to learn how to build one of these technologies, to try out with local farmers.
The low-cost technology they built, called a “chimney solar dryer,” combines continuous air flow with solar heat to dry fresh produce more efficiently than a traditional solar dryer. It was designed by the innovative duo Michael Reid and Jim Thompson, both emeritus specialists with UC Cooperative Extension who have worked on multiple inventions with the Horticulture Innovation Lab. The chimney solar dryer is usually built with basic materials, such as plywood, dark plastic, clear plastic, and food-grade mesh. Read more about how the chimney solar dryer can help farmers add value to crop surplus (PDF).
Here is a quick look at a couple of other technologies that visitors can see at the demonstration center:
A low-cost cold room – equipped with a CoolBot, solar panels and household air conditioner – is on display to show UC Davis visitors one way to cool and store fresh fruits and vegetables off the grid. These visitors were participants in the UC Postharvest Technology of Horticultural Crops short course this summer. Photo by Gregory Urquiaga/UC Davis.
This solar-powered cold room uses a tool designed by an American farmer, called a CoolBot. In a well-insulated room, a CoolBot can trick a household air conditioner into bringing temperatures down low enough for cool storage of fresh produce. Cooling fruits and vegetables soon after harvest from the field can reduce postharvest losses and extend shelf life. So far teams with the Horticulture Innovation Lab have used the CoolBot with farmers in Tanzania, Zambia, Uganda, Thailand, Cambodia, Bangladesh, India and Honduras.
A delegation of deans from agricultural colleges in Ethiopia listen to a short presentation about building a zero-energy cool chamber (ZECC) with bricks and sand, led by Khush Bakht Aalia, center, and Angelos Deltsidis, right, both of the Horticulture Innovation Lab. Photo by Brenda Dawson/UC Davis
The zero-energy cool chamber (known as ZECC) is a simple structure built from brick and sand that can help cool fresh produce, in conditions where evaporative cooling is effective. By regularly wetting the sand and brick, farmers or even marketers can keep the temperatures low and the humidity high for fresh produce such as leafy greens. Researchers with the Horticulture Innovation Lab have been testing what specific conditions — such as hot, arid climates with easy access to water — make this tool effective for farmers to use to cool their fresh fruits and vegetables.
More information about the ZECC is available from the UC Postharvest Technology Center.
Recent visits to the Horticulture Innovation Lab’s demonstration center have come in many shapes and sizes — from people walking by who stopped to read some of the signs, to group activities planned in advance. Recent tours of the center have included a delegation of deans from agricultural colleges in Ethiopia, a television news crew from Tajikistan and high school students from California learning about innovation and human-centered design.
Maybe it will spark an innovative idea that you can use in your fields?
UC Davis and ANR researchers attach clear plastic to a “chimney” frame in Fresno as they work together to build a chimney solar dryer for local growers to try. This low-cost technology was originally designed for Horticulture Innovation Lab researchers to use with farmers in developing countries. From left: Carrie Waterman of UC Davis, Jacob Roberson of UCCE Fresno, UC Davis student Michelle Boutelle, Michael Yang of UCCE Fresno and Angelos Deltsidis of UC Davis. Photo by Archie Jarman/UC Davis
Here is a working chimney solar dryer on the UC Davis campus. Grad student Nick Reitz, left, adjusts the plastic cover over trays of sliced mango with help from Archie Jarman, right, of the Horticulture Innovation Lab. Reitz was practicing using the dryer before working with farmers in Ghana.
This week the Horticulture Innovation Lab Demonstration Center hosted a media crew from Tajikistan, shown here talking with Angelos Deltsidis, center, about using solar dryers for drying apricots in Tajikistan. Photo by Khush Bakht Aalia for the Horticulture Innovation Lab.