The development of two medicinal, aromatic and condimentar species, Mentha piperita (peppermint) and Melissa officinalis (balm) was evaluated in different concentrations of nutritive solution in a NFT hidroponic system of cultivation. Three seeds of these two species were sowed on a fenolical spume (2,5x2,5x3 cm), and irrigated daily with water up to the germination and later with a nutrient solution diluted to 50%. After a period of 15 and 16 days for balm and peppermint, respectively, seedlings were transferred to the development workbenches made with polypropylene channels and received the nutrient solution diluted to 75% during 12 days. After this period, plants were transferred to cultivation on workbenches with different concentrations of nutritive solution until the harvest. The experimental design was conducted completely randomized on split-splot scheme, the concentration of nutrient solution being (I - 50%, II - 75%, III - 100%, IV - 125%) located on the plot and the position of plants in the channels (I - initial, II - intermediary, III - final) on the subplot with a total of three replications per treatment. A total of five plants was used in each position. The evaluated variables were plant height, number of leaves and buds, fresh and dry weight of leaves and roots. Analyzing the position of plants in the channels it was possible to observe significant interaction between treatments and in the number and leaves dry weight of balm and peppermint, respectively, the initial position being the best treatment in terms of plant growth. For balm were observed significant differences between the positions of plants in the channels in relation to plant height, root fresh weight and leaves fresh and dry weight, with the initial position having the higher values, despite of having no significant differences when compared with the intermediary position.
Mentha piperita; Melissa officinalis; plants nutrion; hidropony
