Agronomic and post-harvest characterization of three quality protein maize (QPM) hybrids developed in Ghana

Three 3-way quality protein maize (QPM) hybrid varieties, GHII0-5, GH132-28 and GH2328-88, developed in Ghana were the most productive among several varieties tested between 1994 and 1996 within Ghana and elsewhere in Africa, South America, and East Asia. Yield potentials of the three hybrids ranged from 6.3 to 7.3 t ha-I, representing 19 to 38 per cent yield advantage over the leading pen-pollinated variety, Obatanpa. These were subsequently released in 1997 with the common names, Mamaba. Dadaba and CIDA-ba. respectively. To satisfY the requirement of the Ghana National Varietal Release Committee for their release, and also guide seed growers and germplasm conservators, among others, in their operations, the hybrids were characterized by their agronomic traits, seed characters, and reaction to common foliar diseases. Among the agronomic traits, days to silking, tassel number, tassel arrangement, plant and ear heights, husk cover tightness, and leaf angle were the most useful characters in distinguishing among the three hybrids. The hybrid, GH110-5 (Mamaba), had the least number and the most compactly arranged tassels, and was also the shortest in plant height and ear placement. For the post-harvest characters, GH II 0-5 had the highest number of rows per cob, followed by GH132-28 (Dadaba) and GH2328-88 (CIDA-ba) in that order. Cob length and 1000-seed weight were highest in Dadaba (which was a mixture of flint and dent seeds), followed by Mamaba (flint) and CIDA-ba (dent). The long cobs, high number of rows, flinty nature, and high 1000-seed weight of Mamaba and Dadaba which possibly contributed to their high-yielding potential, are traits that plant breeders should be looking for when developing high-yielding crop varieties. All the hybrids showed high to moderate tolerance to common foliar iseases such as the maize streak virus disease, rust (Puccinia po/ysora), and Bipolaris maydis. The implications of these and other differences.