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Regionalized
technology development and dissemination: The case of breeding for
drought tolerant maize varieties in Tanzania
Z.O. Mduruma
Maize is the single most important staple in Tanzania
produced mostly by smallholder resource poor farmers. It is also an
important source of income for both men and women farmers in villages
where it is sold in local markets. The average yield obtained by farmers
in Tanzania is low, about 1200 kg/ha. Factors contributing to such low
yields include drought, low soil fertility, weeds, insect pests,
diseases and use of poor quality seeds and varieties.
Improved varieties in Tanzania occupy only about 27 percent of
the total area under maize production, mainly due to lack of effective
seed production and distribution systems.
Private seed companies in Tanzania have been able to satisfy less
than 5% of the required certified seed, hence many farmers use recycled
seed of both hybrids and open pollinated maize varieties (OPVs). The
goal of the drought project was therefore to ensure that resource-poor
farmers have access to improved, high yielding maize cultivars that are
suited to their specific farming conditions and preferences. Over the
past five years, Selian Institute maize researchers and colleagues in
southern Africa have focused on developing maize cultivars that produce
good yields under severe drought and low soil fertility. New inbred
lines, experimental OPVs and hybrids are initially screened under
managed drought and low-N. stress conditions. Based on results obtained
from screening sites in Tanzania and across sites in SADC and ECA
regions, promising varieties are selected. These are finally evaluated
in national performance trials (TMVTs) and on farmers’ fields to
assess their preferences, using the Mother/Baby technique.
The varieties which meet the special attributes and farmers’
preferences are then tabled for release to the National Variety Release
Committee of the Ministry of Agriculture and Food Security. During
1998/99 to 2000/01 seasons, these varieties were found to yield 25 to
50% more under drought stress than popular maize varieties. Their
performances and acceptance under resource-poor farmers conditions were
verified in Tanzania through regionalized research efforts. Farmers
mentioned early maturity, drought tolerance, processing quality,
roasting quality and flinty grain type as important traits they seek in
improved varieties. Two improved maize varieties released in November
2001 included SITUKA-M-1 (a drought and low-N tolerant early synthetic
variety tested under the name of ZM 421) and SITUKA-1 (a drought and
low-N tolerant synthetic variety tested under the name of ZM 521).
The satisfactory performance of these varieties has attracted the
attention of breeders, agronomists, extension staff, NGOs and farmers
throughout eastern and southern Africa. These varieties have also been
released in Malawi, Zimbabwe and South Africa.
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