LTRA-5: Agroforestry and Sustainable Vegetable Production

Research Focus

Communities in many forest and vegetable-producing watersheds in Southeast Asia suffer from poverty, while forest, soil, and water resources are being degraded. The objective of LTRA-5 is to develop economically viable and ecologically sound vegetable-agroforestry systems (VAF) and to quantify the potential economic and environmental benefits of these systems. .

Principal Investigator

Manuel R. Reyes
Professor, Biological Engineering
North Carolina Agricultural and Technical State University


VAF is the integration of vegetable crops with trees or trees with vegetable crops – under or beside them, simultaneously or in sequence. The technique has a strong potential to improve quality of life for small-scale farmers. In Vietnam, Indonesia, and the Philippines, researchers are experimenting with a variety of high-value medicinal plants and vegetables, including bell pepper, bok choy, cabbage, cauliflower, melons, and tomatoes; and with cash-crop trees such as cashew. The project is researching various techniques to enhance VAF, such as low-cost drip irrigation, reduced tillage, pest management, reintroduction of indigenous vegetables, and soil enrichment; and offering local workshops to introduce improved cultivation and production practices. Researchers also have conducted baseline household and market surveys that included demographics, household income and expenditures, vegetable market chains, and the role that gender plays in division of labor and farm decision-making.

The project goes by the acronym TMPEGS based on its six main objectives:

Technology. Developing economically viable, ecologically sound VAF systems.
Markets. Conducting market-value chain research at the local, regional, and national levels that builds on existing strategies.
Policy. Identifying options and frameworks that promote sustainable VAF and reward environmental services.
Environment. Evaluating the short- and long-term environmental and socioeconomic effects for farm families who adopt integrated VAF systems.
Gender. Ensuring women's involvement in decision-making and sustainable production and practices.
Scaling up. Building host country capacity to manage and disseminate integrated VAF.

The team, which comprises more than 30 scientists, engineers, and other development experts, works closely with the World Vegetable Center (AVRDC) and the World Agroforestry Center (ICRAF), and has a partnership with international food giant Mars Inc. Its principal investigator (PI) is Manuel Reyes, a biological and agricultural engineer at North Carolina Agricultural and Technical State University in Greensboro.

Research in Vietnam is predominantly with tree systems, especially cashew, the main cash crop. The team has found that cacao can be grown under the cashew canopy, which would give farmers crop diversification and the potential to increase income. Experiments are underway with commercial and indigenous vegetables and root crops, though for now the emphasis is on home gardens for family use. In Indonesia, research is focusing on 11 commercial and indigenous vegetables in VAF systems. In the Philippines, where commercial vegetable farms are a major income source, researchers are investigating how proximity to trees affects vegetable yield and which varieties thrive in the shade. For more information, see the TMPEGS website.

Highlights and Publications

The project is featured as the cover story of NCA&T's 2009 magazine Re:search, published by university's School of Agriculture and Environmental Sciences. Click to see the video of the Re:search interview with Manuel R. Reyes, and read the associated Agroforestry story.

The project recently released a short documentary film, Taming the land, the wind and the sun: The story of the Binahon Agroforestry Farm. Producer for the project was TMPEGS Scaling-Up Coordinator Maria Victoria O. Espaldon, dean of the School of Environmental Science and Management at the University of the Philippines- Los Baños.

TMPEGS member Agnes C. Rola was the lead editor of a book published by SANREM that won the 2007 Outstanding Book Award from the Philippines’ National Academy of Science and Technology. Winning the water war: Watersheds, water policies and water institutions, co-edited by Herminia A. Francisco and Jennifer P.T. Liguton, is a compilation of papers presented at a conference focusing on results of SANREM research.

The Philippine Council for Agriculture, Forestry and Natural Resources Research and Development highlights the book on its website with this summary:

“There is a water crisis, which is aggravated by a flawed governance of water resources. There is a need to empower local government units and communities to address the water crisis. This book presents a holistic analysis of the water situation that focuses on supply and demand conditions as well as on the social, economic, legal and institutional context of the problem. It argues for watersheds as the appropriate planning unit for an integrated water resources management system. It recommends pluralism in the modes in water governance in the country that will enable local stakeholders…to evolve appropriate mechanisms in accordance with local social, political, economic and ecological realities. In sum, the book seeks innovative ways of trying to win the ‘water war’ or of dealing with water scarcity and its related concerns.”

The book is not available digitally. It can be ordered from the Philippines Institute of Development Studies’ publications catalog. To request a copy of the catalog, e-mail