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

Response a/some durum wheat landraces to nitrogen application - Teklu et al.
There was a general increase in GY with an increase in N application rates up to the highest
rate for all the varieties except for DZ 04-118, which decreased beyond 92 kg N/ha
application. The landraces did not significantly differ in GY among themselves, but were
significantly higher than the local as well as the standard checks, which were in turn not
statistically different from each other. B r-9 gave the highest GY (2350 kg/ha) while DZ 04­
118 gave the lowest (2003 kg/ha).
In contrast to the GY, there was no difference in SY among the varieties and their interaction
with N rates. However, there was a significant difference between the SY due to increasing N
application rates. The highest SY (4455 kg/ha) was obtained with application of 115 kg N/ha
while the lowest was with no N fertilization.
SUMMARY AND CONCLUSIONS
The landrace varieties responded to N application rates differently at both locations.
Considering both grain and SY, they generally increased in response to N application rates of
69 and 115 kg N/ha at Akaki (Fig. 1) and Cheffe Donsa, respectively. Generally, the
landraces tended to have advantage over the local as well as the standard checks in their
specific area of adaptation. This is particularly true with respect to SY.
At Akaki, the landrace variety A2-138 gave its highest possible grain and SY with N
application rate of 69 kg/ha. Therefore, farmers of the locality may not need to apply beyond
this rate. For the other varieties, generally the GY increase was up 92 kg N/ha while the SY
increased with further increase ofN rate. He.flce, when GY is the major economic interest, 92
kg N/ha may be optimum provided it is economically paying. In general, reference should be
made to the performance of each variety under specific environmental conditions.
At Cheffe Donsa, both grain and SY increased significantly up to the maximum N
fertilization rate (115 kg/ha). This is particularly significant for the landraces. Therefore,
provided it is economical, higher grain and SY can be obtained with higher N rates,
regardless of the variety.
At both locations, generally the yield was low due to the prevailing heavy waterlogging as a
result of the heavy rainfall and low permeability of the nearly saturated Vertisols. The use of
improved drainage could increase yield by 50-100% (Abate et al., 1993) under such
conditions. Hence, N fertilization should be combined with surface drainage to achieve
economically and ecologically attainable yield. Since the response to N fertilization can be
affected by the availability of other nutrients such as P, factorial experiments should be
carried out to fine-tune the recommendation.
REFERENCES
Abate Tedla, M.A. Mohamed-Saleem, Tekalign Mamo, Alemu Tadesse and Miressa Duffera. 1993. In:
Tekalign Mamo, Abiye Astatke, K.L. Srivastava and Asgelil Dibabe (eds.). pp. 103-137. Improved
management of Vertisols for sustainable crop-livestock production in the Ethiopian highlands:
Synthesis Report 1986-92. Technical Committee of the Joint Vertisols Project, Addis Ababa, Ethiopia.
Desta Beyene. 1988. Soil fertilizer research on some Ethiopian Vertisols. In: S.C. Jutzi, Haque, r. McIntire, J.
and J.E. Stares (eds.). pp. 223-231. Management of Vertisols in sub-Saharan Africa. Proceedings of a
Conference held at ILCA, 31 Aug. - Sept., 1987. Addis Ababa, Ethiopia.
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