Symptoms of Cu, Zn, Mn and B toxicity in ornamental Vriesea

Abstract

Commercial production of ornamental bromeliads involves high production standards and imperfect plants are often not tolerated. However, due to their highly efficient nutrient uptake and tendency towards luxury consumption, Bromeliaceae are prone to accumulate various micronutrients which might result in leaf damage. Therefore the tolerance of Vriesea to high concentrations of different micronutrients was investigated in this report. Application of Cu, Zn, Mn and B at approximately 10× the concentrations normally used in commercial Vriesea culture did not result in visible leaf damage. Application at approximately 50×the regular concentrations did result in leaf damage: Cu lead to necrosis, Zn resulted in a red discoloration of the leaf tips while Mn and B had no visible effects on plants. Analysis of leaf tissue by ICP confirmed that Cu, Zn, Mn and B accumulate to high concentrations in the leaves. When high levels of Cu, Zn, Mn and B are applied together instead of individually, this results in minimal damage and lower internal concentrations of each element. These results show that except for Cu, there is little risk of leaf damage occurring due to excessive application of micronutrients in Vriesea cultivation.