Abstract

PALEMON ALBERTO, Francisco et al. Maize intervarietal crosses productive potential in the semi-warm region of Guerrero. Rev. Mex. Cienc. Agríc [online]. 2012, vol.3, n.1, pp.157-171. ISSN 2007-0934.

In the semi-warm regions of Guerrero (about 1 500 m elevation) prevails sowing with native seeds (Landrace), but there are also areas where improved maize can be established. In this paper we propose two intervarietal crosses as an alternative for farmers to increasing grain production, and these were selected after evaluating the agronomic performance of five parent varieties and their possible crosses in a factorial arrangement; two of them of tropical origin selected at least 10 generations to adapt to the Highlands and the other three from native subtropical germplasm, obtained in the State of Guerrero; also, besides the six intervarietal crosses and their parents, the local variety of the farmer and six varieties as a control were added to evaluate in a randomized complete block design with four replicates in the spring-summer, 2009, in two localities of intermediate elevation. The combined analysis across the environments showed significant differences in grain yield among crosses, parents and the controls. The VS-529*VE-1 and VS-529*VE-3 intervarietal crosses were higher in grain yield to their parents, the local variety of the farmer and commercial controls had other attributes, such as better ear health and plant expression intermediate for plant height, days to male and female flowering, and less lodging. The subtropical parent varieties per se were slightly higher in grain yield, ear weight and ear diameter compared with the tropical varieties, but they had slightly better health of plant and ear. Parents VE-1, VE-3 and VS-529 had positive general combining ability (GCA) effects; their crosses were those that showed higher grain yield, heterosis, earliness, better-looking plant and ear, while CIST and SINT-3-HE exhibited negative GCA effects. These results allowed to selecting the intervarietal crosses with favorable agronomic characteristics and production potential acceptable as an option to support the traditional corn of intermediate areas of the State of Guerrero.

Keywords : Zea mays L.; general and specific combining ability; heterosis; grain yield; tropical and subtropical varieties.