Responses of sweet pepper (Capsicum annum L.) cultivated in a closed hydroponic system to variable calcium concentrations in the nutrient solution

Summary

Abstract BACKGROUND The use of water containing calcium bicarbonate (Ca(HCO3)2) at excessively high concentrations in closed hydroponic crops can cause calcium ion (Ca2+) accumulation in the recycled nutrient solution (NS) and concomitantly negatively affect yield and product quality. The aim of the study was to determine maximum Ca2+ concentrations that do not harm the crop and to simulate the pattern of Ca2+ accumulation when the Ca2+ concentration in the irrigation water, and concomitantly in the replenishment nutrient solution (RNS), is excessive. In the current study, irrigation water containing 1.5, 3.0, 4.5 and 6.0 mmol L−1 Ca2+ was used to prepare the RNS supplied to pepper cultivated in a closed hydroponic system. RESULTS At 1.5 mmol L−1 Ca2+, no Ca2+ accumulation was observed in