Condutividade elétrica da solução nutritiva no cultivo sem solo de couve rábano

Abstract

ABSTRACT The electrical conductivity of the nutrient solution directly affects production and quality of the plants. We evaluated the electrical conductivity suitable for soilless cultivation of kohlrabi. The experiment was carried out in a completely randomized design, with four replicates and five treatments, composed of different nutrient solution’s conductivities (1.31, 1.71, 2.37, 2.98 and 3.75 dS m-1). We evaluated number of leaves, leaf area, specific leaf area, leaf area ratio, fresh and dry masses of leaves, bulb, roots and total, bulb volume, water content in the bulbs and pH, soluble solids, vitamin C, firmness, titratable acidity and SS/TA ratio of the bulbs. All variables related to growth were affected by the nutrient solutions, showing the highest values with the use of the nutrient solutions with EC close to 2.0 dS m-1. Considering the commercial part of the plant, the most developed bulbs were obtained with EC of 1.96 dS m-1, being 49.9 g and 41.15 cm3 per bulb. On the other hand, except for pH, the other variables responded to the increase of EC. Higher values for pulp firmness and titratable acidity occurred with EC close to 2.0 dS m-1, whereas the other variables showed higher values using a more concentrated nutrient solution.