Advances in Improving Harvest Index and Grain Yield of Maize in Ethiopia

Abstract

The local maize varieties are inefficient in transferring assimilates to the ear sink and as a result they are low yielding. To replace these low yielding local varieties by high yielding ones, different breeding methods have been used in Ethiopia. This study was undertaken to compare improved maize varieties released in Ethiopia for their harvest index and other important agronomic traits. Twelve improved maize varieties which were released from 1970s to 1990s in Ethiopia and 8 breeding populations were tested in a randomized complete block design at Bako Agricultural Research Centre under sub-optimum and optimum soil fertility conditions in 1997 and 1998. The analysis of variance for harvest index and other important agronomic traits showed significant differences (P<0.01) among the varieties. The mean harvest index varied from 31.1% (Bako composite) to 45.0% (BH-540), indicating wide differences among the varieties in partitioning the photosynthate into grain and vegetative plant part. The mean grain yield also varied from 4.3 t ha^-1 (EAH-75) to 7.2 t ha^-1 (BH-660). All the varieties released in the 1990s had a better harvest index than the old maize composites, indicating the breeding progress made was successful for both grain yield and harvest index. Further progress in maize breeding to improve harvest index and grain yield would be possible with the use of refined breeding methods and tools.

Keywords: Genotype; Grain Yield; Harvest Index; Maize Varieties; Zea mays L.

East African Journal of Sciences Vol. 1 (2) 2007: pp. 112-119