Biomass production, nutritional requirement of nitrogen, phosphorus and potassium, and concentration of the nutrient solution in oregano

Abstract

The concentration of nutrient solution (NS) in soilless culture systems influences the accumulation of aerial biomass and nutrient contents. This research aimed to determine the optimal Steiner NS concentration for biomass production in Greek oregano (Origanum vulgare L. ssp. hirtum [Link] Ietswaart), and to quantify its nutritional requirement of nitrogen, phosphorus and potassium. A completely randomized design was established with five treatments and five replicates. The treatments were different NS concentrations: 25, 50, 75, 100 and 125 %. The experimental unit consisted of five bags (20 x 20 cm) with substrate (tezontle: 3 to 10 mm in diameter), with one plant each. The fresh and dry aerial matter and the concentration of N, P and K in the different samples were determined. The results showed significant statistical difference in the five variables. The highest fresh and dry matter production was obtained with the 50 and 75 % NS concentrations. While the lower concentrations did not meet the crop’s nutrient demand, the higher concentrations significantly decreased biomass production. The 50 % NS can be used in commercial hydroponic oregano production. The nutritional requirement of this crop is: 4.76 kg of N, 0.70 kg of P and 5.10 kg of K, per ton of fresh matter.