Nairobi, Kenya
October 18, 2007Source:
The Alliance for a Green
Revolution in Africa (AGRA)
Cassava, Africa’s second most important food crop
after maize, is under siege by viruses that have
decimated much of the crop across the continent.
Following a recent spike of cassava brown streak
disease (CBSD), cassava breeders from across
sub-Saharan Africa met in Zanzibar, Tanzania earlier
this month to discuss introducing new
disease-resistant varieties of cassava to help
preserve this food crop that is critical for poor
farmers across Africa.
The meeting was hosted by
the Alliance
for a Green Revolution in Africa (AGRA), and
Tanzania’s Ministry of Agriculture. AGRA is chaired
by Kofi Annan and supported by the Rockefeller
Foundation and the Bill & Melinda Gates Foundation.
Cassava is a cheap source of nutrients and is a
staple food for some 250 million Africans. It
tolerates drought and is able to thrive in marginal
soils making it one of Africa’s most reliable food
crops.
Tanzania’s cassava breeders have developed resistant
materials that could be critical to arresting the
epidemic. The key will be getting this genetic
material to other breeding programs, and working
with governments to speed release of the new
varieties. The breeders are urgently seeking ways to
get the new, hardier cassava seeds to farmers.
One solution already underway through AGRA is by
developing farmer entrepreneurship to combat the
problem. In Zanzibar, each village designates a
farmer who will be in charge of growing
disease-resistant cassava. |
With support from the Alliance
for a Green Revolution in Africa (AGRA), network pPlans new
breeding strategies, urges regulatory action
A meeting of Africa’s leading cassava breeders zeroed in on
actions needed to stop the rapid spread of cassava brown streak
disease (CBSD). The resurgent crop disease has already caused a
low-grade famine in northern Mozambique, and led Zanzibar
farmers to largely abandon cultivation of the critical food
crop. Breeders from Uganda, Kenya, Tanzania, Malawi and
Mozambique all noted the rising threat of the disease to
small-scale farmers in their areas.
The agricultural scientists, meeting in Zanzibar 3-5 October
2007, said that the disease has recently spiked, for reasons
that are unclear. Yet, breeders have already developed a number
of disease-resistant varieties, and others are in the pipeline.
Breeders noted that the problem lies in getting these varieties
to farmers. They noted that many African governments have
stringent variety release rules that seriously delay getting the
new varieties into farmers’ fields.
“Joint action by cassava breeders, farmers and government
agencies can contain this disease,” said cassava breeder, Dr.
Edward Kanju, of the International
Institute for Tropical Agriculture (IITA), in Tanzania.
“Isolated action or inaction will worsen hunger. Unless cassava
scientists and policy makers understand that there is this
menace, farmers and their families will suffer as a result.”
If CBSD continues to spread unabated, the damage would be
considerable, breeders said, and would compound the losses
already being caused by a second disease, the African cassava
mosaic virus. CBSD causes the edible cassava roots to become
corky and inedible, and may also streak and destroy leaf tissue.
Once introduced into a field, the virus can spread rapidly, and
yield losses of up to 100 percent have been registered. However,
Tanzania’s cassava breeders have developed tolerant materials
could be critical to arresting the epidemic. The key will be
getting this genetic material to other breeding programs in the
region for use in local breeding programmes.
Across Africa, cassava is a staple food for some 250 million
Africans, and its tuberous root is the second most important
crop in terms of calories consumed. It has served as a reserve
against famine and is tolerant to water stress and poor soils,
making it important to African farmers facing longer and more
frequent droughts. Its leaves are used as a vegetable and
provide a cheap but rich source of proteins, vitamins A, B and
C, and other minerals. Cassava’s importance to Africa has even
been recognized by the African Union’s New Partnership for
Africa’s Development (NEPAD), which has developed a Pan African
Cassava Initiative. Nonetheless, cassava remains susceptible to
a number of crop diseases and pests, and most varieties grown by
small-scale farmers are low yielding, limiting the crop’s
potential to alleviate hunger and malnutrition.
Breeders and Farmers Working Together to Increase Yield and
Tackle Disease
The breeders noted that while curbing the spread of cassava
brown streak disease is a top priority, breeding strategies also
need to increase cassava yield and to target specific traits
that farmers are looking for, otherwise farmers are unlikely to
use the new varieties.
Yield increases will not only stem hunger, but are also
essential to conserve African environments, according to Dr.
Ibrahim Benesi, a cassava breeder with the Chitedze Agricultural
Research Station in Lilongwe, Malawi.
He noted that cassava production in Africa has grown from 90 to
145 million tons in the last forty years and, at that production
is expected to double in the next twenty years. “However, more
than 75% of this increase in cassava production has come from
increases in land area rather than increase in productivity.
Farmers need to harvest more on less land if African
environments are to be spared,” Benesi said.
Network breeders recommended a new breeding strategy, known as
“farmer participatory selection” as key to the development of
varieties that are disease resistant, high yielding, and appeal
to farmers. Using this approach, crop breeders involve local
farmers directly in their work to identify farmer preferences,
which may involve things such as taste, good cooking ability,
early maturity, good storage in the ground, more roots per
plant, pest and disease resistance, and leaves suitable as a
good vegetable. The approach ensures that qualities for disease
resistance and yield are coupled with qualities important to
local farmers and communities.
“This farmer-participatory approach to plant breeding is a
genuine and fairly recent breakthrough in crop breeding,” said
George Bigirwa of AGRA. “Only a decade ago, such methods were
considered by many to be ‘less scientific’ than selecting for
maximum yields in trials grown on isolated research stations
using high applications of fertilizers and chemical pesticides.”
At the meeting, cassava breeders from eight countries reported
on the farmer participatory breeding work of their national
research institutions. In many cases, the reports represented
the first time that the breeders were testing their own locally
developed varieties, rather than varieties developed by others
at distant research stations.
Building Farmer Entrepreneurs and Strengthening
Private-Sector Involvement
Some network participants also stressed the urgent need to
increase private-sector involvement in supporting small-scale
cassava farmers and building markets.
Zanzibar is blazing one approach to the problem. The government
has not only approved four new CBSD-tolerant varieties, but is
working across the region to spur farmer entrepreneurial
efforts.
On Zanzibar’s two islands, cassava had been the most important
crop after rice—until a severe outbreak of cassava brown streak
disease practically wiped it off the map. With the support of a
small AGRA grant, the government, breeders and farmers are
taking an innovative approach to restoring the crop. The
government has already approved several CBSD-resistant
varieties, and it has initiated a farmer-led variety
distribution program. Instead of centrally distributing cuttings
from the Ministry of Agriculture, each village will designate
its own farmer responsible for growing the disease-resistant
varieties and distributing them, at a low set cost, to local
farmers.
“With the support of AGRA, we will train farmers themselves to
multiply and disseminate cassava planting materials to other
farmers rather than relying on companies,” said Mr. Haji Saleh
of the Ministry of Agriculture of Zanzibar. “This system will
make sure farmers are able to access these new varieties of
cassava while at the same time empowering them with
entrepreneurial skills.”
The African Cassava Breeders Network meeting brought together
nearly 50 people from eight countries: Kenya, Uganda, Tanzania,
Mozambique, Nigeria, Ghana, Malawi and Rwanda. Present were crop
breeders, seed producers, and representatives of
agriculture-related businesses and non-governmental
organizations. The meeting was jointly convened by AGRA and the
Ministry of Agriculture of Tanzania.
The Alliance for a
Green Revolution in Africa (AGRA) is a dynamic partnership
working across the African continent to help millions of
small-scale farmers and their families lift themselves out of
poverty and hunger. AGRA programs develop practical solutions to
significantly boost farm productivity and incomes for the poor
while safeguarding the environment. AGRA advocates for policies
that support its work across all key aspects of the African
agricultural “value chain”—from seeds, soil health, and water to
markets and agricultural education.
AGRA is chaired by Kofi A. Annan, the former Secretary-General
of the United Nations. AGRA, with initial support from the
Rockefeller Foundation and the Bill & Melinda Gates Foundation,
maintains offices in Nairobi, Kenya and Accra, Ghana. |
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