Horticulture & Tree Systems

In sub-Saharan Africa (SSA), smallholder tree systems and indigenous and exotic vegetables and fruits provide a lifeline for both rural and urban or peri-urban communities.

Tree crops such as cocoa, coffee, oil palm, and rubber; and vegetables (tomato, peppers, aubergine, carrot, cabbage, amaranth, African nightshade, and lettuce) and fruits (coconut, cashew, mango, and citrus) support the income of Africa's rural poor. They complement existing staple cropping systems and provide cash crops for export and value-added production, enhancing livelihoods and sustaining biodiversity. They also provide food and nutritional security for producers and consumers.

For instance, the cocoa sector of West and Central Africa accounts for 70% of global output and has experienced growth rates of over 4% per annum over the last 20 years, largely due to area expansion. Yield growth has been less than 1%, however. As a result, incomes of cocoa-growing households have stagnated while deforestation has continued unabated. Among the factors contributing to low productivity are pests and diseases, old tree stocks, limited use of improved planting material, low use of agrochemicals, and inadequate extension support.

Planting these indigenous and exotic fruits, vegetables, and tree crops results in better use of land, water, and labor. Such systems, however, are plagued by many biological and socioeconomic challenges, including low yield, numerous pests and diseases, inefficient use of pesticides, inadequate access to environmentally friendly inputs, poor access to improved planting materials, lack of information on appropriate agronomic and pest management practices, limited access to market information and credit sources, underinvestment, and weak supportive policies.

R4D goal

Our R4D work provides opportunities to make horticultural and tree systems more productive by introducing improved seed distribution systems, integrated crop and pest management practices, new market opportunities, and value addition. We develop and promote sustainable production and postharvest technologies, and influence enabling policy and marketing environments that enhance productivity and increase income.

We address challenges and opportunities through research and effective public-private partnerships in a value chain approach. These are undertaken through two centerpiece programs: the IITA/SDC Vegetable Integrated Pest Management (IPM) Project and the Sustainable Tree Crops Project (STCP) with various international, regional, and national partners including the private sector.

R4D outputs and outcomes

IITA/SDC Vegetable Integrated Pest Management (IPM) Project
We identified botanicals as alternatives to chemical nematicides for carrots and gboma (African eggplant). We used the fungus Beauveria bassiana to manage Lepidopteran pests such as diamondback moth in cabbage, which could not be controlled by synthetic pesticides.

We work at reducing chemical pesticide dependence in cotton through the development of sustainable pest control methods using biopesticides and botanical products. We are also developing control methods for coconut mite using classical biological control or natural pest enemies.

We are developing and implementing a sustainable pest management program for major mango pests, such as the invasive fruitfly, Bactrocera invadens, in SSA through improved biological control (classical and inundative) and IPM technologies.

In Benin, for instance, we promote IPM awareness on negative effects of synthetic pesticides and by developing and promoting biological-based options against key pests on selected vegetables. We also conducted training of trainers and farmer field schools (FFS) on integrated plant production and plant protection of gboma, cabbage, carrot, and lettuce, and food safety quality.

Intensified Tree Crop Systems
Currently, the project focuses mainly on cocoa in West and Central Africa, with additional work on cashew, mango, and oil palm in West Africa and coffee in East Africa.

Approaches, such as farmer field schools and participatory video, and institutional arrangements have been developed for training cocoa farmers in Cameroon, Cote d'Ivoire, Ghana, Liberia, and Nigeria. Trained farmers got 15-40% higher cocoa yields, while requiring 10-20% less pesticides. Notably, the video viewing club method piloted in Ghana won the 2008 CGIAR award for outstanding communications.

Increase in cocoa income of households averaged between 23% and 55% as a result of production and marketing interventions. National institutions have expressed eagerness for integrating these training approaches into their programs. For example, the FFS approach has been declared by the National Cocoa Development Committee as the primary cocoa extension mechanism for Nigeria.

STCP also serves as a platform for regional collaboration on research to address the genetic basis for improved cocoa plants, pest and disease management, and rehabilitation and diversification of cocoa farms, resulting in the development of local research capacity across the region.

Through this program, we provide millions of small-scale farmers with the tools, technologies, and solutions that could help enhance livelihoods, and food and nutritional security, sustain biodiversity, and transform horticulture and tree systems into vehicles for economic development.

Projects

Horticulture & tree systems documents