Maize is one of the most important staple crops in the highlands of the Andean region of Ecuador, Peru, and Bolivia. Most seeds come from landraces, with their own kernel characteristics. The kernels are used for the elaboration of traditional dishes and other elaborates for human consumption. In this region, maize breeding is conducted mainly by public institutions. In this review, we outline the methodology that has been used by the maize breeding programs (MBPs) of the National Institutes for Agricultural Research and other institutions in the highlands of Ecuador, Peru, and Bolivia during the last 20 years. The main objective of MBPs in the region has been to develop more uniform and productive open-pollinated varieties (OPVs) of floury maize (Zea mays L. var. Amylacea), which is the most important type of maize in the area. Participatory plant breeding, combined with half-sib, has been used to breed new maize varieties. At least 18 OPVs of floury maize have been released into the Andean region in the last 20 years. Breeding this type of maize has been very important to conserve diversity and promote consumption in the region, but they have had very little impact on yield. The yield of floury maize is around three times below that of dent or semident maize grown in the region. Therefore, there is a need to apply new breeding techniques in the region to accelerate the development of more productive floury-maize cultivars.

Yellow maize (Zea mays L. var. indurata) is mainly produced in the Ecuadorian lowlands (less than 1,200 m a.s.l.), primarily for feed production. Although Ecuador has recently increased maize production, new genotypes are needed for self-sufficiency and in order to avoid costly imports. Maize is sown mostly from December to January during the rainy season. However, the irregularity of rainfall has become a constraint on production. “INIAP H-603 Superior” is a new single-cross maize hybrid developed for the Ecuadorian lowlands with improved yields, which could contribute to domestic food security. The new hybrid had an average yield of 8.48 t ha-1 with outstanding performance under the rainfall, sustained moisture, and irrigation conditions, outperforming the commercial hybrids INIAP H-602, DEKALB-7088 and INIAP H-553. Additionally, the new hybrid showed tolerance to the principal foliar diseases: leaf blight (Exserohilum turcicum), rust (Puccinia sorghi), and leaf spot (Curvularia lunata), as well as good adaptability and stability, with a regression coefficient (bi) of 0.98 when it was evaluated in 29 locations from 2010 to 2013. The greatest yield potential of the new hybrid (10.82 t ha-1) was obtained with irrigation during the dry season.