Some parameters in relation to iron nutrition status of peach orchards

Abstract

This study was conducted to determine DTPA extractable iron contents and some soil properties of peach (Prunus persica L.) orchards, total and 1N HCl extractable iron contents of leaves and investigate their relations with chlorosis. For this purpose, nine peach orchards, each of which included green, slightly chlorotic and severe chlorotic peach trees, were selected. Soil and leaf samples were taken from these orchards for chemical analysis. Soil samples were collected from the top 30 cm and from a 30-60 cm depth from the soils under the peach trees variously affected by iron induced chlorosis. Soil analysis revealed that results, in the top 30 cm, soil extractable iron contents were negatively correlated with pH, EC and lime (r= -0.260*, -0.621** and -0.298**) respectively. Negatively significant correlations between extractable iron and exchangeable cations, were also found, but correlations were positively significant with organic matter at both soil depths (r=0.595**, 0.608**). Most of the DTPA extractable soil iron contents were found higher than the critical concentration range (4.5 mg kg-1) despite visually and analytically iron chlorosis determined in the plants. DTPA method is not capable of estimating and monitoring of iron chlorosis in the plants grown on calcareous soils. 1 N HCl extractable active iron contents of the leaves were found relevant with the chlorosis degrees (r= -0.839**) and recognized as a better nutritional iron indicator than total iron.