Introduction

Sorghum is one of the crop types for which Ethiopia has been credited as being a Vavilovian centre of origin or diversity (Harlan, 1969). In the different ecological zones of the country, germplasm resources representing the major and intermediate races of sorghum are found. In addition, the existence of wide variation in plant, grain, inflorescence and fruit characteristics in the Ethiopian sorghum germplasm is well documented (Gebrekidan, 1973; Gebrekidan & Kebede, 1977). Among the sorghum growing population in the rural areas, the importance of this crop is exemplified not only by its use as a staple food and for other purposes, but also in the folklore, songs and some of the local names by which the sorghum varieties are known.

As one of the leading traditional food cereals in Ethiopia, in terms of both total production and area, major research efforts have been directed towards the improvement and stabilization of sorghum yields. At a national level, sorghum improvement involves the manipulation of indigenous and introduced germplasm to develop adapted types for the various ecological zones. In crop improvement work the indigenous germplasm has been found invaluable (Gebrekidan, 1981).

Periodic sorghum germplasm collections made throughout the country have provided the sources of breeding material necessary for the sorghum improvement programme. In the high altitude areas the indigenous germplasm has often been the only adapted material suitable for use. From evaluations of germplasm collections, potential varieties have been identified.