Distribution of macro- and micronutrients in leaves, roots, and scapes of gerbera affected by calcium and humic acid

Abstract

Different levels of humic acid (HA) (0, 100, 500, and 1000 mg L−1) and Ca (3.5 and 7 meq/L) were applied to growth media. A multi-level factorial experiment with a completely randomized design was employed with three replicates to evaluate interaction effects. Macro- and micro-nutrient contents were measured in leaves, roots, and scapes of gerbera. Five hundred mg/L HA increased macro- and micronutrients (P, N, K, Mg, Ca, Fe, and Zn) contents of leaves, roots, and scapes. High HA levels reduced some nutrient contents. The 7 meq/L Ca significantly increased Fe and Zn contents of leaves and roots and K and Mg contents of roots, and had no significant effect on other macronutrients. The results showed the importance of Ca-HA treatment in gerbera cultivation through increasing nutrient concentration. The Ca-HA treatment exhibited significant effects on nutrient uptake of gerbera. Ca and HA combination was more effective, especially with 7 meq Ca and 500 mg/L HA, than the low Ca and HA content. The 7 meq/L Ca and 500 mg/L HA increased N, Ca, K, and Zn concentrations in leaves, and Ca, P, Mg, Fe, and Zn concentrations in scapes, and Zn in roots, whereas this trend for Fe, Mg, and N in leaves and P and Mg in roots was found in 100 and 1000 mg/L HA. Conclusively, nutrients’ absorbtion and accumulations in scape and leaves were higher than in roots and were higher when Ca was applied in 7 meq/L with HA at 500 mg/L to gerbera.