Investigation of zinc nutriton and relationships between zinc nutrition and some plant growth regulators of citrus orchards in the Kumluca and Finike regions

ABSTRACT INVESTIGATION OF ZINC NUTRITION AND RELATIONSHIPS BETWEEN ZINC NUTRITION AND SOME PLANT GROWTH REGULATORS OF CITRUS ORCHARDS IN THE KUMLUCA AND FİNİKE REGIONS Selim TOKMAK Ph.D. Thesis in Department of Soil Science Adviser: Prof. Dr. A. Turgut KÖSEO?LU March 2001, 161 pages In this research, zink (Zn) nutrition of citrus orchards and relationships between zinc nutrition and some plant regulators (IAA, ABA, Cytokinin, GA3) were investigated in the Kumluca and Finike regions. For this purposes, during two years period, soil, leaf and shoot samples were taken from 17 orchards for the first and 28 for the second year, and necessary analyses were performed. In the second year, hormone analyses of leaf and shoot samples taken from 16 orchards, which were determined by the results of total and active zinc concentration, were analyzed. The study revealed that 47 % of the soil for the first and 42.9 % for the second year had sufficient level of available zinc, whereas 52.9 % of them for the first and 57.1 % for the second year had not sufficient levels of available zinc. 70.6 % of the leaves samples taken within the first year was found to be low levels and 29.4 % to be sufficient levels in terms of available zinc content. For the second year, it was seen that 78.6 % of the leaves samples had low levels of available zinc although 21.4 % of the samples showed sufficient levels. Considerable relationships were found between zinc and hormone content, among the hormone content, and between the hormone content and plant nutrients in the leaves and shoots. Negative correlation has been observed between active zinc and ABA in the top leaves, positive correlations have been observed between active zinc in the top leaves and ABA in the shoots, and active zinc and acidic kinetin in the top leaves. On the other hand, positive correlations have also been observed between basic kinetin in the shots and IAA in the leaves, acidic kinetin and ABA in the shoots, GA3 in the leaves and IAA in the shoots, and GA3 and IAA in the shoots. At the same time same correlations have been found between Mn and ABA, and Mn and GA3 content of the leaves. KEY WORDS: Washington Navel orange, plant growth şeffclator, ABA, IAA, Kinetin, GA3, active Zn,HPLC. COMMITTEE: Prof. Dr. A. Turgut KÖSEO?LU Prof. Dr. Nevin ERYÜCE ^^ Prof. Dr. Mustafa KAPLAN