Growth, flower production and mineral nutrition in gerbera (Gerbera jamesonii H. Bolus) plants grown in substrate culture with and without nutrient solution recycling

The aim of this work was to investigate if gerbera plants show significant differences in growth and flower production when grown in two different soilless growing systems, with and without nutrient solution recycling. Several parameters were measured and calculated: Dry matter production and allocation, flower yield, quality and mineral nutrition. Growth indices did not show significant differences between the two systems. Nutrient concentration inside the substrate was lower in the closed system, possibly due to recycling of nutrient solution. Analysing mineral contents in dry matter luxury consumption of Nitrogen, Phosphorus and Potassium was found in the open growing system, but it did not have an effect on production and quality of flowers. Total flower production was 12.5 per plant, while diameter and stem length were, respectively, 10-12 and 40 cm in both systems. Moreover, the amount of nutrient lost per year was calculated measuring the nutrient concentrations in the drainage solution. Results showed that about 93 N, 6.8 P, 165 K and 107 Ca Kg·ha-1 per year are released into the environment.