EFFECTS OF CITRUS ROOTSTOCKS ON SOME PLANT NUTRIENT ELEMENTS ABSORPTION OF GRAFTED CULTIVARS

Citrus rootstocks have prime effects on the size of tree and fruit, quality of fruit and micorhyza dependence, which make difference in their leaf mineral elements concentration in leaf of grafted cultivars on them. A pot factorial experiment with two factors including rootstocks (sour orange, Citrange, Rough Lemon, Citrumelo and Yozo) and grafted cultivars (Thomson Navel, Sanguine, Unshiu Tangerine) was carried out in farm conditions with three replications. The studied traits were concentrations of elements in leaves including nitrogen, phosphorus, potassium, sulfur, magnesium, iron, manganese, zinc and copper. The result of analysis of variance revealed significant mean squares of variety, rootstock and their interaction effects for the elements in leaves. Citrumelo rootstock had mainly effect on nutritional elements in leaves. Unshiu mandarin with Citrumelo rootstock had the most amount of nitrogen and sanguine variety with Citrange rootstock made the highest concentration of phosphorus and potassium in leaves of the grafted cultivar. Significant positive correlation of K with Fe and Zn indicating that all rootstocks with high mean value of K in leaf of grafted cultivar will have high amount of Fe and Zn. Significant positive correlation also detected between N and P of leaf of grafted cultivars in combination with different rootstocks; therefore, most of combinations with high mean value of N had also high mean value of P. Unshiu Tangerine had high variation for P, but Thomson Novel had lowest variation for this mineral element. Due to Significant positive correlation of S with Mg and Mn, most of rootstocks with high amount of S in leaf of grafted cultivar had high mean values of Mg and Mn in their leaf of grafted cultivars.