First Report of Leaf Spot Caused by Alternaria alternata on Kiwifruit in Italy

Abstract

A leaf spot of kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang & A. R. Ferg.) leaves was recently observed on plants of the cultivar Hayward in an orchard near Salerno, in southern Italy. The affected plants showed early severe defoliation. The fungus isolated from the infected leaves was identified as Alternaria alternata (Fr.:Fr.) Keissl., based on conidial morphological characteristics. Pathogenicity tests were made by inoculating detached leaves of male pollinator cultivar Tomuri and the female cultivars Hayward and Bruno with a 7-mm disk taken from actively growing cultures of the fungus on potato dextrose agar (PDA). After 14 days, necrotic leaf spots developed and A. alternata was consistently isolated from the inoculated leaves. A. alternata has been observed as a pathogen on leaves and fruits in New Zealand. In the Mediterranean, it has been reported in Israel (2) and in the island of Crete (1). This is the first report of Alternaria leaf spot on kiwifruit in Italy. References: (1) V. A. Bourbos and M. T. Skoudridakis. Petria 7:111, 1997. (2) A. Sive and D. Resnizky. Alon Hanotea 41:409, 1987.