Effect of relative humidity on foliar absorption of P and Rb by Chrysanthemum and Pilea

Abstract

Air humidity differentially affected the foliar absorption of <sup>33</sup>P and <sup>86</sup>Rb by <i>Chrysanthemum morifolium</i> 'Giant # 4 Indianapolis White' and <i>Pilea cardierei</i>. As the relative humidity increased from 47 to 80% in most cases, there was in increase in uptake. Further raising of humidity to 92% increased uptake of Rb and P by <i>Chrysanthemum</i> leaves only when guttation did not occure . Air humidity influenced most strongly the uptake of calcium phosphate probably due to its low solubility.