Response of Citrus rootstocks to iron deficiency under high pH conditions

Abstract

Turkey is one of the major citrus producing countries in the Mediterranean Basin. Approximately 90% of the total citrus production in Turkey is carried out in the Mediterranean Region. Soil of the Mediterranean region is calcareous and because sour orange is tolerant to high pH, the rootstocks is widely used in this region. Sour orange rootstock, which is well adapted to calcareous soils, has positive effects on yield and quality, but is extremely sensitive to Citrus Tristeza Virus disease. Because sour orange is very sensitive to tristeza, there is a need to find an alternative rootstock that is well adapted to calcareous soils and has good fruit yield and quality. For this purpose, 16 citrus rootstock and genotypes could be used as a rootstock, were tested against high-pH conditions for iron chlorosis in growth chamber. At the end of this experiment, Tuzcu 891 sour orange, Gou Tou sour orange and Antalya Cleopatra mandarin were the most tolerant; Duncan grapefruit, Tuzcu 31-31 sour orange, Sunki mandarin, Nasnaran mandarin, Cleopatra mandarin x Swingle citrumelo hybrid, Carrizo citrange, C-35 citrange and Marumi kumquat were moderate tolerant; Volkameriana, Swingle citrumelo, Pomeroy trifoliate and Sarawak bintangor were sensitive; and a local trifoliate was found to be the most sensitive to iron chlorosis in a high pH medium. Index terms: rootstock, iron deficiency, leaf chlorophyll concentration. Resposta de porta-enxerto de Citrus a deficiência de ferro sob condições de alto pH RESUMO