Plant improvement has closely followed human development. Wheat, rice and maize were originally wild grasses, but selection and improvement over millennia has produced the world’s most important staple crops. The same is true for other grains like millet, sorghum and quinoa, an array of vegetables, vines, flowers and popular fruit-bearing trees and a few timber species. Other trees, which nonetheless provide a range of useful products and services, have not been so lucky.
Dr. Ramni Jamnadass, leader of the World Agroforestry Centre’s (ICRAF’s) Global Research Priority on Quality Trees, believes trees are often taken for granted. “Trees are some of the world’s longest living species, and because of this people have assumed they will always be here” she says. “Although little has been done in recent decades to domesticate and improve useful trees, with a little investment great strides are possible.” With support from international development partners, ICRAF is currently one of a handful of international research centres in the world involved in tree domestication.
Jamnadass led the production of a just-released training publication dealing with this topic. Agroforestry Tree Domestication: A Primer, developed by ICRAF scientists and partners, is a synthesis of material developed from training workshops on tree domestication that ICRAF has offered over the past decade or so to scientists, development workers and community groups from all regions of the tropics. The five-module volume lays out the technical and community-related processes involved in tree domestication. Equipped with this knowledge, those trained will be able to conceptualise, implement and manage tree domestication initiatives where they work.
“For hundreds of years, communities have depended on forest trees to provide products like fruit, timber and medicines, but these forests are shrinking and the trees are now threatened. ICRAF believes that the future of such trees is on farms, providing alternative sources of products and taking pressure off remaining natural stands. This is exactly what we hope to achieve through the domestication of useful trees, bringing them into wider cultivation in farmers’ fields” says Jamnadass. “Wild tree species harbour as yet unknown products that could find application in medicine and other spheres, and these must not be lost to us,” she adds.
Domestication means selecting desirable traits from wild species and developing propagules with these properties that can be grown on farms and sold in markets. Many different techniques are used. Some of the approaches used—such as vegetative propagation or seed production—can be handled well by farmers, but other methods, such as the use of molecular markers for genotyping, need workers with specialised training. Scientists must work closely with communities, using participatory domestication approaches where possible to enhance adoption and accelerate impact.
For real impact, tree domestication must go hand in glove with programmes to deliver quality planting material of selected trees to the millions of farmers who want them. Delivery systems to get tree planting material distributed to farmers through nursery networks and small private enterprises is the subject of another recent ICRAF publication titled Falling by the wayside: improving the availability of high-quality tree seeds and seedlings would benefit hundreds of millions of small-scale farmers.
Success in tree domestication, when it comes, is sweet: domestication of safou (Dacryodes edulis) and bush mango (Irvingia gabonensis and I. wombolu) has brought welcome additional income to smallholder farmers and tree nursery owners in Cameroon. Fruit is eaten by farmers and sold, boosting household nutrition and revenues. ICRAF Director General Tony Simons says this is the clear end-goal: “From this initiative, our intention is that smallholders’ livelihoods will benefit through a ‘second wave’ of plant domestication that builds on the evolution of crop plants and is focused on tree species that are currently underutilised and understudied, but have significant value.”
