TY - PRO AU - Lyimo,N.G. AU - Ransom,J.K.|Palmer,A.F.E.|Zambezi,B.T.|Mduruma,Z.O.|Waddington,S.R.|Pixley,K.V.|Jewell,D.C. ED - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico) TI - Progress towards hybrid maize development in the Southern Highlands of Tanzania SN - 92-9146-025-7 U1 - 633.15 PY - 1997/// CY - Addis Ababa (Ethiopia) PB - CIMMYT KW - Highlands KW - Tanzania KW - Varieties KW - AGROVOC KW - Zea mays KW - Hybrids KW - Plant breeding KW - CIMMYT N2 - The southern highlands (SH) of Tanzania constitute an important maize growing zone, accounting for over 46% of total maize production in the country. Hybrid maize is widely accepted in this zone, however, farmers have relied on old, relatively low yielding, non-uniform hybrid varieties for a long time. In order to address this problem, inbred line development was initiated in the late 1980's, in order to generate new hybrid varieties for the high and intermediate elevation maize growing areas of the country. Inbred lines developed from high and intermediate altitude maize germplasm have shown promising results in top cross evaluation trials across locations in the SH. Top crosses involving high altitude inbred lines showed high grain yield potential, as several entries exceeded the commercial hybrids H6302 and H614 by over 20%. In top cross evaluation trials for the intermediate elevation zone, several entries outyielded the commercial hybrids C6222 and C4142 in a similar manner. These results indicate the possibility of generating a set of high yielding top cross hybrids for the two agro-ecological zones, as a first step towards solving the problem of hybrid seed quality in the SH, to be followed by further work towards the formation of three-way and single crosss hybrids ER -