Growth, yield and leaf nutrient content of organically grown banana plants in the Canary islands

Abstract

Introduction. To compare the mineral nutrition of organically and normally grown banana plants, observations were made on growth and yield of organic banana plants, at the Canary Islands. The data were then discussed opposite the results previously reported for conventional plantations. Materials and methods . Growth parameters (plant height, leaf emission rate, pseudostem circumference) and yield parameters (bunch weight, number of hands, finger grade, etc.) were measured during ten months on an organically grown banana plantation of Dwarf Cavendish cv. Leaf N, P, K, Ca, Mg, Cu, Fe, Mn and Zn contents were also assessed. Results and discussion . Leaf emission rates showed higher values in late spring and early summer (0.099-0.109 leafd-1 ), while pseudostem circumference grew more in late spring (0.238 cmd-1 ) than in summer. In August, pseudostem circumference decreased dramatically, probably because the plants with a larger circumference had flowered before that month and could not be measured. Bunches gave good yields for the zone (43.59 kg on average) and had a high mean number of hands (12.79). Number of fingers of the second upper hand (25.63), their grade (37.63 cm), length (23.50 cm) and weight (165.19 g) ranged from normal to high. Month of harvesting influenced yield and quality of the fruits. Leaf content of N, P, Mg, Cu, Fe, Mn and Zn fell within the normal range related to the conventionally grown banana plants. Potassium foliar content showed low levels but not deficiencies, whereas Ca leaf concentrations were high but not excessive. No relationship was found among leaf nutrient levels and growth, yield and fruit quality parameters.