INFLUENCE OF FERULIC ACID, P, K AND CA ON GROWTH AND MINERAL NUTRITION OF LETTUCE (LACTUCA SATIVA L.) IN SOILLESS CULTURE

To study the effects of a phenolic acid on growth and mineral composition of lettuce, plants were cultivated for seven days in nutrient solutions containing 0, 10, 100 or 1000 μM ferulic acid (FA). Three experiments were conducted, where the nutrient solution concentration of K, P, or Ca, was varied. In all experiments, the highest concentration of FA (1000 μM) reduced root and shoot dry weights, root:shoot ratios, and plant uptake of K, P, Ca, and Mg. There was a strong, significant interaction between the concentration of FA and the level of K in the nutrient solution for the uptake of K in the plant. At 1000 μM FA, root concentrations of Ca, Cu and B increased in all experiments.