Breeding Quality Protein Maize (QPM): Protocols for Developing QPM Cultivars

This manual is intended for maize breeders who would like to start developing quality protein maize (QPM) cultivars. It is a compilation and consolidation of several breeding protocols successfully used at CIMMYT over two decades of QPM development and breeding. A brief background and the basic theory of QPM genetics are explained, leading up to detailed methods and procedures of QPM development.Zea mays, Plant breeding, Breeding methods, Genetic resources, Protein quality, Protein content, Application methods, Lysine, Tryptophan, Food composition, Crop Production/Industries, F30, Q04,

Mejoramiento de ma�z con calidad de prote�na (QPM): Protocolos para generar variedades QPM

Zea mays, fitomejoramiento, m�todos fitot�cnicos, recursos gen�ticos, calidad de prote�na, contenido de prote�na, m�todos de aplicaci�n, lisina, tript�fano, componentes de los alimentos, Crop Production/Industries, F30, Q04,

Agronomic potential of “Dodzi”, an extra early-maturing maize cultivar

Production of short-cycle crop varieties reduces the risk of crop loss due to terminal droughts and ensures early harvest to fill the hunger gap. Two experiments were used to determine the yield potentials of elite extra-early (75- 80 days) maturing maize (Zea mays L.) varieties to recommend the best extra-early variety for commercial productionand use in Ghana. In the first experiment, two extra-early and eight early (90-95 days) maize varieties were evaluated in replicated field trials at 10 research stations in 1995 and 1996. In the second experiment, thetwo extra-early varieties, one recommended early variety, and the farmers’ check variety were evaluated at 38 and 28 farm sites in 1995 and 1996, respectively. Mean grain yields across the 10 on-station sites in 2 years were 3.5, 4.1, 4.6, and 3.4 t ha-1 for NAES EE W-SR (extraearly), NAES Pool 16 DT (extra-early), Dorke SR (early), and the farmers’ check variety, respectively. Mean yields of the four varieties across 66 farm sites in both years were 3.2, 3.4, 3.4, and 3.6 t ha-1, respectively. NAES EE W-SR was the earliest of all the varieties tested and the farmers’ variety was latest. Food preference tests showed that NAES EE W-SR was comparable to the farmers’ check variety in suitability for local dish preparations. The National Variety Release Committee subsequently approved and released NAES EE W-SR under the local name “Dodzi”. “Dodzi” is recommended for early planting and harvesting throughout Ghana

Agronomic potentials of quality protein maize hybrids developed in Ghana

A quality protein maize (QPM) hybrid programme was started in 1991 to develop and promote high and stableyielding QPM hybrids to increase production of nutritionally superior maize varieties in Ghana. Six 3- way QPM hybrids developed from inbred lines originating from germplasm of the International Centre for Maize and Wheat Improvement (CIMMYT) were evaluated on research stations and in farmers\' fields in Ghana from 1995 to 1996. In the on-station evaluations, grain yields across 10 sites in both years averaged 6.0 ton ha-1 for the three hybrids (GH132-28, GH110-5 and GH2328-88), 5.22 ton ha-1 for Obatanpa, and 3.60 ton ha-1 for the local maize variety. In farmers\' fields, data from over 50 farm sites in 1995 and 1996 showed mean yields of 4.95 ton ha-1 for the three hybrids, and 4.28 ton ha-1 for Obatanpa compared to 3.59 ton ha-1 for farmers\' varieties. On the average, the hybrids were similar to Obatanpa in days to 50 per cent silking, but were shorter in plant height and ear placement. Consumer preference tests showed that the three hybrids were rated similar to the local variety in popular traditional food preparations such as ‘kenkey\' and ‘tuo zafi\'. In 1997, the National Variety Release Committee approved the release of GH132-28, GH110-5, and GH2328-88 under the local names Dadaba, Mamaba, and CIDA-ba, respectively. These hybrids are recommended for planting in all the major agro-ecologies to boost maize production in Ghana.Les variétés de maïs hybride (Zea mays L.) dont les plus sésirées que les variétés de pollinisation libre à cause de leur uniformté et leurs potentiels de rendement plus élevés. Pour augmenter la production de variétés de maïs nutritionnellement supérieures au Ghana, I\'Institut de Recherche de Cultures a mis en place un programme hybrid de maïs protéique de qualité (MPQ) en 1991 pour développer et promouvoir des hybrides de MPQ de rendement élevés et stable. Six hybrids en trois de MPQ développés d\'issu de la même souch provenant de germeplasmes de CIMMYT (Centre International pour I\'amélioration de maïs et de blé) étaient évalués aux stations de recherches et aux champs d\'agriculteurs au Ghana de 1995 à 1996. Dans les évaluations sur place, les rendements de grain à travers 10 sites dans les deux années ont atteint la moyenne de 6.0 ton ha-1 pour les trois hybrids (GH132-28, GH110-5 et GH2328-88), 5.22 ton ha-1 pour \'Obatanpa\' et 3.60 ton ha-1 pour la variétés de maïs local. Sur les champs d\'agriculteurs des données de plus que 50 sites de champs en 1995 et 1996 montraient les rendements moyens de 4.95 ton ha-1 pour les trois hybrids et 4.28 ton ha-1 pour les \'Obatanpa\' comparées à 3.59 ton ha-1 pour les variétés d\'agriculteurs. En moyenne, les hybrides étaient semblables à \'Obatanpa\' en jours jusqu à 50% d\'apparition de soie maïs étaient plus courtes en taille de plante et en placement d\'épi. Les essais de préférence de consommateur montraient que les trios hybrides étaient évalués semblables à la variété locale dans les préparations de nouriture traditionnelle populaire telle que \'kenkey\' et \'tuo zafi\'. En 1997, le comité pour la mise en vente de Variété Nationale a approuvé la mise en vente de GH132-28, GH110-5 et GH2328-88 sous les noms locaux respectifs de Dadaba, Mamaba, et CIDA-ba. Ce hybrides sont recommandés pour la popultion dans toutes les agroéclogies majeures pour stimuler la production de maïs au Ghana. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 81-8

Studies on performance of some open-pollinated maize cultivars in the Guinea savanna. III. Nitrogenuse efficiencies of four cultivars

Nitrogen use efficiency (NUE), defined as grain produced per unit of fertilizer nitrogen (N) applied, is a highly desirable agronomic character of non-leguminous crop varieties. This study was conducted to compare the NUEs of one local maize (Zea mays L.) variety and three improved composites released in Ghana since 1972, and determine the effects of breeding for improved agronomic performance on the NUEs of the improved cultivars. The four late-maturing maize cultivars (local, Composite 4,Dobidi, and Okomasa) were evaluated at 0, 80, and 160 kg N ha-1 and under three plant densities at Nyankpala and Damongo in 1992 and 1993. Across environment analysis for grain yield showed environment, plant density, nitrogen, and cultivar effects were significant (

Studies on performance of some open-pollinated maize cultivars in the Guinea savanna. II. Genetic contribution to productivity of four cultivars under varying population and nitrogen regimes

Three late-maturing varieties of maize (Zea mays L.) released from 1972 to 1988 and one local cultivar were evaluated in replicated field trials at Nyankpala and Damongo in 1992 and 1993. Plant densities (30 000, 50 000, 70 000 plants ha-1) were assigned to the main-plots and 12 combinations of N fertilizer levels (0, 80, 160 kg N ha-1) and varieties (Local, Composite 4, Dobidi, Okomasa) were assigned to the sub-plots in four replicates. The objective was to determine the rate of increase in grain yield due to genetic improvement under the different levels of soil fertility and plant densities. Across location analysis for grain yield showed significant (

Studies on performance of some open-pollinated maize cultivars in the Guinea savanna zone of Ghana. 1. Effects of plant density, nitrogen level and their interactions on yield

Plant density and nitrogen (N) fertilizer responses of one local and three improved open-pollinated cultivars of maize (Zea mays L.) developed in different eras of maize breeding were studied on sandy-loam Alfisols in the Guinea savanna zone of Ghana in 1992 and 1993. A split-plot design was used in which plant densities (30 000, 50 000, 70 000 plants/ha) were the main-plots and 12 combinations of N fertilizer levels (0, 80, 160 kg N/ha) and cultivars (Local, Composite 4, Dobidi, Okomasa) were the sub-plots in four replicates. A cross location analysis for grain yield showed environment, plant density, nitrogen and cultivar effects were highly significant (

Optimum planting dates for four maturity groups of maize varieties grown in the Guinea savanna zone

Five maize varieties, comprising NAES EE W SR (extra-early, normal maize (NM)), Dorke SR (early, NM), Abeleehi (intermediate, NM), Obatanpa (intermediate, quality protein maize) and Okomasa (late, NM), were sown at 2-week intervals from mid-May to last week of July in 1993 and 1994 at Nyankpala in the Guinea savanna zone. The varieties were assigned to main-plots and planting dates to sub-plots in the randomized complete block with four replications per year. Effects due to variety and planting date were highly significant (P< 0.01) for grain yield. The variety W planting date interaction was not significant for yield. Grain yields averaged over planting dates were 3890, 5252, 5798, 5830, and 5883 kg/ha for the varieties NAES EE W SR, Dorke SR, Abeleehi, Obatanpa and Okomasa, respectively. Grain yields for the six sowing dates averaged over varieties were 5919, 5900, 6232, 4895, 4537 and 4502 kg/ha. Grain yields for the first three planting dates did not differ significantly from each other. Similar results were obtained for the last three planting dates. Yields on the average were 30 per cent higher for the first three planting dates than for the last three. Plant dry matter yield, number of ears per plant and thousand grain weight were the parameters which showed significant positive correlations with grain yield among planting dates. The data showed that (1) for all maturity groups, maize sown from mid-May to mid-June significantly out-yielded the later plantings, (2) the extra-early and early maize varieties were lower yielding than the later varieties, and (3) there was no yield advantage in the late varieties over the intermediate types in the Guinea savanna zone. (Ghana Journal of Agricultural Science, 1997, 30(1): 63-70