Investigation of iron status and comparison various analysis methods for determination of iron chlorosis in apple trees in Elmalı and Korkuteli regions

ABSTRACT INVESTIGATION OF IRON STATUS AND COMPARISON OF VARIOUS ANALYSIS METHODS FOR DETERMINATION OF IRON CHLOROSIS IN APPLE TREES IN ELMALI AND KORKUTELİ REGIONS Sahriye SÖNMEZ PhJ). in Soil Science Adviser: Prof. Dr. Mustafa KAPLAN January 2002, 184 pages This study was conducted to investigation the iron status and to determine the most suitable methods to be used in evalution of iron chlorosis in apple trees in Elmalı and Korkuteli regions, Antalya. For this purpose, 22 apple orchard in Elmalı and 16 apple orchard in Korkuteli were selected for leaf and soil analysis. Leaf samples were collected from green and chlorotic trees of the orchards and soil samples were taken in these orchards from 0-30 and 30-60 cm depths. Analyses of pH, CaC03, HCO3, EC, texture, organic matter, N, P, K, Ca, Mg, Fe, Mn, Zn and Cu on the soil samples and analyses of N, P, K, Ca, Mg, Fe, Mn, Zn and Cu on the leaf samples were carried out. In order to determine iron concentration with different methods, methods of 1 N HC1 (method I), 0.1 N HC1 (method IT), 0.005 M DTPA (method m)and % 1.5 o-phentration (method IV) on dried leaf samples and analyses of total chlorophyll and peroxidas activity on fresh leaf samples were carried out. The soils of the regions were found to be light alkalin and alkalin, generally very highly and extremely calcerous, non-saline, medium and heavy textured, poor in organic matter. In terms of N, P, K, Ca and Mg of the soil samples were sufficient; Fe and Zn of the soils were inclasses which were unsufficient and might show unsufficient. Mn and Cu of the soils in the regions were at sufficient level. Although N, P, Ca, Mg, Fe, Mn and Cu of the leaf samples were sufficient, K and Zn were unsufficient. The total N, Ca, Fe and Mn contents of the green leaf samples were found significantly higher than those of chlorotic leaves. P and K contents of green leaf samples were lower than chlorotic leaves; Mg, Na, Zn and Cu contents of green leaves were not found significantly different. The total chlorophyll, peroxidas activity, the content of Fe determined by method I, method EL, method TV and the total Fe contents of the green leaves were higher than chlorotic leaves, but the contents of Fe determined by method II were not found significantly different. According to the results, in terms of the contents of total chlorophyll and peroxidas activity, It was found that 1 N HCl method was the most suitable method amongst the methods used in this study; but due to low correlation coefficient with standart methods (total chlorophyll and peroxidas activity), it is concluded that this method should be further developed. KEY WORDS: Active Iron, Total Iron, Iron Analyses, Iron Chlorosis, Total Chlorophyll, Peroxidas Activity, Apple. COMMITEE: ProfDr. Mustafa KAPLAN Prof. Dr. Turgut KÖSEO?LU Prof Dr. Rıfat YALÇIN 11