Agronomic Performance, Adaptability, and Stability of Maize Hybrids under Tropical Conditions in Ecuador

Maize is one of the most planted and consumed cereals worldwide. Environmental conditions are essential in the genotype x environment interaction and its productive potential. During the rainy season of 2016, 2017, and 2018, the agronomic, phytosanitary, productive, and adaptive potential were consecutively evaluated in 18 hybrids of yellow corn in five localities with tropical environments: Lodana, Jipijapa, and Tosagua (Manabi); Mocache (Los Rios); and Zapotillo (Loja). Analysis of variance and comparison of means with Tukey's test (p <0.05) were used to determine the effect of hybrids between and within environments. The parameters of adaptability and stability were estimated using the bi-segmented regression method. Phytosanitary characteristics correlated significantly with productive ones. Likewise, grain yield correlated significantly with cob insertion height, plants harvested per plot, number of cobs harvested, aspect of cob, and rust. The genotype x environment interaction analysis showed a differentiated hybrid response in each environment. Genotype G1 (G.I.2.10-1-1-1xL.I.4) was the best adapted to most localities, showing higher yields than the other materials. In contrast, Genotype G10 (G.I.3.39-3-11xPORT.PHAEO.1AS2.4-1-1-1) was the most responsive to favorable environments. Promising hybrids G1, G2, G3, G5, G7, G9, and G11 could be of interest for favorable environments, while G8 could be explored for unfavorable environments. Jipijapa, Tosagua, and Zapotillo had the best potential for corn production in at least two years of evaluation, with Tosagua being the most stable in producing corn hybrids in Ecuador.