PHYSIOLOGICAL CHARACTERISTICS OF SOME FRUIT TREE SPECIES AFFECTED BY FUNGAL PATHOGENS

Abstract

This study analyzed the physiological effects of the pathogens Venturia inaequalis (Cooke) Winter on Malus domestica (Suckow) Borkh. and Stigmina carpophila (Lév.) M.B. Ellis on Prunus armeniaca L. Pathogen attack reduced the photosynthetic rate in both species due to the appearance of necrotic leaf lesions, a decrease in photosynthetic surface area, and structural damage; concurrently, the transpiration rate declined as a result of disrupted water balance, associated with tissue damage, reduced leaf area, and altered stomatal activity. Infected leaves also exhibited a slight decrease in water content, accompanied by an increase in dry matter content. Chlorophyll content decreased by 10.8 % in Malus domestica and by 6.9 % in Prunus armeniaca. The results indicate that both pathogens negatively affected photosynthesis, water relations, and assimilatory pigment content, with the physiological impact being more pronounced in apple trees infected by Venturia inaequalis.