Abstract Plantain is an important crop for Ecuador due to its contribution in socio-economy and food security of this country, supplying rich-energy food to most of the population; in addition, it is necessary to carry out fertilization management that allows a better use of this resource and increase the yield. Magnesium fertilization in ‘Barraganete’ (Musa AAB) plantain was evaluated in El Carmen, Manabí, Ecuador. The research was conducted in the Experimental Farm “Rio Suma”, Universidad Laica Eloy Alfaro de Manabí, Extension El Carmen, located at 260 masl, average temperature of 24 .C, annual rainfall of 2 684 mm. Six levels of MgO (0, 25, 50, 75, 100, 125 kg·ha−1) were applied to know its effect on morpho-physiology and plant yield. A completely randomized block design with six treatments and three replications was used; the sowing was carried out with a distance of 2.50 m × 1.80 m (2 222 plants·ha−1), and the variables of vegetative growth were evaluated as repeated measures over time. The results demonstrated significant differences in all the morpho-physiological variables, which showed that fertilization with 30% MgO affected the growth of the plants; however, the reproductive variables were not affected by the applied doses; the 25 kg·ha−1 dose generated the best yields, agronomic efficiency and partial productivity factor.

Resumen El cultivo de plátano es importante por el aporte que genera en la socio-economía y seguridad alimentaria de Ecuador, pues suministra alimentos ricos en energía a la mayor parte de la población. Además, se hace necesario realizar manejos de la fertilización que permitan una mejor utilización de este recurso e incrementar los rendimientos. Por ello, se evaluó la fertilización con magnesio en plátano ‘Barraganete’ (Musa AAB) en El Carmen, Manabí, Ecuador. La investigación se condujo en la Granja Experimental “Rio Suma”, Universidad Laica Eloy Alfaro de Manabí, extensión en El Carmen, ubicada a 260 msnm, temperatura promedio de 24 .C, precipitación anual de 2 684 mm. Se aplicaron seis niveles de MgO (0, 25, 50, 75, 100, 125 kg·ha−1) para conocer su efecto sobre la morfo-fisiología y el rendimiento de las plantas. Se utilizó un diseño de bloques completos al azar con seis tratamientos y tres repeticiones; la siembra se realizó con un distanciamiento de 2,50 m × 1,80 m (2 222 plantas·ha−1), y las variables de crecimiento vegetativo se evaluaron como medidas repetidas en el tiempo. Los resultados demostraron diferencias en todas las variables morfo-fisiológicas, lo que demostró que la fertilización con 30% de MgO afectó el crecimiento de las plantas; no obstante, las variables reproductivas no fueron afectadas por las dosis aplicadas; la dosis de 25 kg·ha−1 generó los mejores rendimientos, eficiencia agronómica y factor parcial de productividad.

Resumo Plátano é a quarta cultura mais importante do mundo, considerada um produto básico e de exportação do Equador. A distribuição radicular de três cultivares de plátano (Musa AAB) cultivadas no Equador foi avaliada na Fazenda Experimental “Río Suma”, Universidade “Laica Eloy Alfaro de Manabí”, 0º15 ‘S, 79º26’ W. As cultivares de plátano foram ‘Barraganete’, ‘Curare Enano’ e ‘Dominico Hartón’, e a distribuição radicular foi determinada de acordo com a fenologia das plantas (10; 20; 30 e 40 folhas (inflorescência) e colheita), semeadas a 2,5 m x 1,8 m. Em um delineamento de blocos inteiramente casualizados, com cinco repetições, cinco plantas·cultivar-1 foram selecionadas para cada avaliação. A distribuição radicular foi realizada em perfis de solo entre as linhas. A maior distribuição radicular ocorreu de 20 cm lateralmente, até 40 cm de profundidade. Longitudinalmente, as raízes de ‘Curare Enano’ ocorreram até 60 cm, ‘Dominico Hartón’, 50 cm e ‘Barraganete’, 40 cm; a 40 cm de profundidade, ‘Barraganete’ e ‘Curare Enano’ tinham raízes de até 30 cm de comprimento e ‘Dominico Hartón’ de até 50 cm. A distribuição radicular das três cultivares pode estabelecer critérios de manejo agronômico para determinar a densidade de plantas, a fertilização e a irrigação.

Abstract Plantain is the fourth most important crop in the world, considered as a basic and export product in Ecuador. The root distribution of three plantain cultivars (Musa AAB) grown in Ecuador was evaluated at the “Río Suma” Experimental Farm, “Laica Eloy Alfaro de Manabí” University, 0º15’ S, 79º26’ W. Plantain cultivars were ‘Barraganete’, ‘Curare Enano’ and ‘Dominico Hartón’, and root distribution was determined according to the phenology of plants (10, 20, 30, 40 leaves (inflorescence) and harvest), seeded at 2.5 m x 1.8 m. In a completely randomized block design with five replicates, five plants·cultivar-1 were selected for each evaluation. Root distribution was carried out in soil profiles between rows. The greatest root distribution occurred 20 cm laterally, up to 40 cm in depth. Longitudinally, ‘Curare Enano’ roots occurred up to 60 cm, ‘Dominico Hartón’ (50 cm) and ‘Barraganete’ (40 cm); at 40 cm in depth ‘Barraganete’ and ‘Curare Enano’ had roots up to 30 cm in length and ‘Dominico Hartón’ up to 50 cm. The root distribution of the three cultivars can establish agronomic management criteria to determine plant density, fertilization and irrigation.