Adaptation and grain yield of quality protein maize hybrids in Mexican tropical and subtropical regions.

A partir de 1998 se inició un programa nacional de maíz con el fin de desarrollar, identificar y liberar híbridos y variedades de alta calidad de proteína con mayor potencial de rendimiento, adaptados a diversas regiones productoras. En el presente trabajo se predijo el comportamiento de cruzas triples a partir de un análisis conjunto de rendimiento de un dialélico formado con 10 líneas de alta calidad proteínica liberadas por el CIMMYT, que fueron evaluadas en cinco localidades de México durante 1997. Las cruzas triples predichas fueron evaluadas en 11 localidades tropicales y subtropicales de México durante el ciclo primavera-verano 1999. En los resultados obtenidos se observó que algunas cruzas triples predichas produjeron rendimientos similares a las cruzas simples de alta calidad proteínica y a los testigos comerciales normales. Los híbridos que mostraron mayor adaptación a través de localidades involucraron cruzamientos entre líneas tropicales por subtropicales. En regiones tropicales (Iguala, Guerrero) se obtuvieron rendimientos experimentales de hasta de 10 t/ha y en regiones subtropicales (Celaya, Guanajuato) hasta de 16 t/ha. Las cruzas triples predichas constituyen una buena alternativa en países con climas tropicales y subtropicales donde el uso de las cruzas simples, aún no se ha generalizado debido a problemas de producción de semilla, con la ventaja del carácter de alta calidad proteínica para las regiones donde el consumo de maíz es significativo.A national quality protein maize program was initiated to develop, identify and release high yield potential quality protein maize hybrids and varieties adapted to different regions. Three-way crosses were predicted, based on 10 quality protein maize inbred lines diallel, which were evaluated at five Mexican locations during 1997. The predicted three-way crosses performance were evaluated at 11 tropical and subtropical Mexican locations during 1999. The superior group of predicted three-way crosses showed a good performance in almost all locations. They were competitive in grain yield with quality protein maize single crosses and normal commercial hybrids. The three-way quality protein maize hybrids with the best adaptation across locations were hybrids which involved tropical and subtropical inbred lines. In tropical regions the highest grain yield (10 t/ha) were obtained at Iguala, Guerrero. In subtropical regions the highest grain yield (16 t/ha) were obtained at Celaya, Guanajuato. The predicted three way hybrids are considered a good alternative for countries with tropical and subtropical climate were the use of single crosses is not common yet, because of seed production problems, with the advantage of quality protein maize character for regions where maize consumption is significant