Response of Lisianthus (Eustoma grandiflorum Raf.) Cv. Echo Blue to Different Nitrogen Concentrations

Lisianthus is an ornamental species that is little known probably because it is not widely cultivated by flower growers; in consequence, research on mineral nutrition is scarce. Lisianthus is becoming an interesting alternative for cut flower production because consumers are enticed by its very attractive, delicate flowers and extended vase life. The objectives of the present study were to determine the response of lisianthus to varying concentrations of nitrogen (N) in the nutrient solution, to establish the N concentration associated with higher quality of cut flowers, and to define the distribution of dry mass and nutrients in plant organs. The effects of N concentration in the nutrient solution (0, 50, 100, 150, 200, 250, 300, 350, 500 y 600 mg·L^-1) on growth, nutrimental status, dry mass and mineral nutrient distribution, and vase life were studied. Plants grown with solutions containing N at 100 and 250 mg L^-1 exhibited the best growth, biomass accumulation and vase life. Leaf N concentration on these plants was from 2.16 to 3.22%, which may correspond to the sufficiency levels of lisianthus, and were associated with increased leaf calcium and potassium concentration, decreased magnesium, and modified dry mass and nutrient distribution in plants. Dry mass distribution exhibited the following ranking: stems>leaves>roots=flowers.