The Eleventh Regional Wheat Workshop For Eastern ... - Cimmyt

ON-FARM EVALUATION OF THE RESPONSE
OF FOUR BREAD WHEAT VARIETIES TO NITROGEN FERTILIZER
IN KARATU DISTRICT IN NORTHERN TANZANIA
H.A. Mansoor 1 , R.V. Ndondi l , D.O. Tanner2, P. Ndakidemi l and R.T. Ngatokewa 1
ISelian Agricultural Research Institute, P.O. Box 6024, Arusha, Tanzania
2CIMMYT/CIDA Eastern Africa Cereals Program, P.O. Box 5689, Addis Ababa Ethiopia
ABSTRACT
Wheat research in Tanzania has been dominated by on-station research with an
orientation for large-scale mechanized farms. This approach failed to address the
real problems and constraints facing small- to medium-scale wheat fanners.
Thus, an on-farm trial was established in 1997 at Rhotia and Mbulumbulu
villages in Karatu district in the Northern Zone of Tanzania to evaluate the
performance of three improved wheat varieties and their response to applied N
fertilizer. The wheat varieties included Mbayuwayu, Kware, Tausi and a local
fanners' variety; the N rates used were 0, 30, 60 and 120 kg Nlha. Combined
analysis across locations and years indicated significant variety and N effects; the
two- and three-way interactions were all non-significant. Across the range of
wheat seed and grain prices considered in the economic analysis, the wheat
variety Kware was economically optimal. Application of 30 kg Nlha was also
economically optimal across a range of fertilizer and wheat grain prices. The
current results provide a sound basis for recommending the wheat variety K ware
and an N rate of30 kglha for small-scale wheat farmers in northern Tanzania.
INTRODUCTION
Agricultural research in Tanzania has been dominated by on-station research, and the results
generated by this research have often been translated into recommendations for small-scale farm
production under varied environments. This approach failed to account for the actual constraints
confronting the small-scale farming community. The majority of the fanners in Tanzania can be
described as small-scale resource poor farmers, and these have gained little from the process of
technology transfer. New technologies should be evaluated and verified under farmers'
management condi'tions prior to making recommendations either on a national or a regional
scale. Tanzanian scientists have yet to fully understand the diverse and complex environments in
which resource poor farmers operate. In order to increase the relevance and, hence, adoption of
agricultural interventions such technologies must be developed under fanners' conditions.
During the period between 1970 to 1994, several bread wheat varieties were released by the
Selian Agricultural Research Institute (SARI) for large-scale mechanized wheat farms based at
the Hanang Wheat Complex. As a result, wheat yields increased from an average of 0.5 to 8
bags/acre (Nyaki et at., 1993). However, small- and medium-scale farn1ers have not benefited
from the released wheat varieties, as well as the other components of the production package
developed during that period, because there was no evaluation under the relevant environments .
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Low soil fertility, exacerbated by sub-optimal farming practices such as the removal of crop
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