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

RESPONSE OF SOME DURUM WHEAT LANDRACES
TO NITROGEN APPLICATION ON ETHIOPIAN VERTISOLS
Teklu Erkossa, Tekalign Mamo, Selamyihun Kidane and Mesfin Abebe
Debre Zeit Agricultural Research Center, P.O. Box 32, Debre Zeit, Ethiopia
ABSTRACT
Landrace durum wheat constitutes one of the major cereals grown on Vertisols
in the central highlands of Ethiopia. Their productivity is limited, among other
factors, by low soil fertility, including nitrogen deficiency. Consequently,
inorganic N fertilization is recorrunended at a rate of 60 to 90 kg N/ha for
improved durum wheat varieties under different cropping systems. However,
little information is available on the differential response of landraces to
applied N. This led to the initiation of a field experiment at two representative
Vertisol locations, Akaki and Cheffe Donsa, in the central highlands. The
experiment was conducted for three years (1993-1995) on three promising
durum land race genotypes (A2-138, EI-9 and Bl-9 for Akaki, and A2-187
and Bl-9 for Cheffe Donsa). Kilinto and DZ04-118 for Akaki, and DZ0320
and DZ04-118 for Cheffe Donsa were used as local and standard checks,
respectively. Six levels of N (0, 15, 30, ,60, 90 and 115 kglha) were used in
factorial combination with the lanQraces and checks. The results showed that
the effects of N rate were significant on both grain and straw yields at both
locations. Differences among the landraces were significant for both grain and
straw yields at Akaki, but only for grain yield at Cheffe Donsa. The interaction
effects of landraces by N rates were significant in two out of the three years on
grain and only one out of the three years on straw yield at both locations.
Generally, grain and straw yields increased with N level while the biological
optimum for each was different. The landraces tended to have an advantage
over the local and the standard checks in their specific areas of adaptation,
paIiicularly with respect to straw yields. Hence, emphasis should be directed
towards determining the economic optimum rate of N application on Vertisols
for optimum wheat grain and straw production.
INTRODUCTION
On Veliisols of the central highlands, a mixture of several tetraploid wheats which are
suitable for making unleavened bread and pasta products are predominant. They cover about
60% of the total area devoted to wheat production (Hailu, 1991) with mean GY s estimated at
around 1 t ha- I , and hence contribute roughly 10% to the annual cereal production in Ethiopia
(Tesfaye and Getachew, 1991). In recent years, study for the identification of genotypes with
good yield is underway. Their release at their respective original collection sites is hoped to
improve the current poor yields.
With fertilizers becoming impOliant inputs to maximize crop yield and nitrogen fertilizer
being determinant in durum wheat, several N fertilizer trials have been undertaken to
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