Effects of calcium on phytotoxicity of foliar‐applied nitrogen salts

Abstract

Leaf strips or intact plants of Salvia splendens were exposed to phytotoxic levels of ammonium and/or nitrate salts, and the modifying effect of Ca was investigated. The addition of CaCl₂ to a bathing solution in which leaf strips were immersed was found to reduce nitrogen salt induced damage to leaf strips, which was indicated by reduced leakage of UV absorbing constituents with increasing concentrations of CaCl₂. Leakage was 74% in a 0 M CaCl₂ plus 0.1 M NH₄NO₃ in the bathing solution, and 7% in a 0.1 M CaCl₂ plus 0.1 M NH₄NO₃ in the bathing solution. Attempts to reduce foliar damage on a whole plant basis by either adding CaCl₂ to NH₄NO₃ sprays, by preloading plants with Ca, by pretreating the plants with foliar sprays of Ca(NO₃)₂, or by root pretreatment with CaCl₂, did not succeed in reducing foliar damage from NH₄NO₃.

Notes

Texas Agricultural Experiment Station Article No. 24935. Address reprint requests to D.W. Reed.