Casual agents of leaf spot disease of common privet (Ligustrum vulgare L.)Przyczyny plamistości liści ligustru pospolitego (Ligustrum vulgare L.)

Abstract

As a result two-year investigations conducted in productive nurseries on one-, two-, threeand four-year-old seedlings of common privet the occurrence of powdery mildew, anthracnose and leaf spot disease were stated. Leaf spot diseases and necroses on common privet leaves were caused by a complex of filamentous fungi with a prevalence of Alternaria alternata, Epicoccum purpurascens, Phomopsis cf. ligustri-vulgaris, Botrytis cinerea and Cercospora ligustri. Fungi, monophagous to common privet, such as: Ph. cf. ligustrivulgaris, C. ligustri, Septoria cf. brunellae and Thedgonia ligustri were recorded among the casual agents of leaf spot disease. Oneyear-old seedlings of common privet were the most susceptible to infection with A. alternata and E. purpurascens necrotrophs. The highest intensity of leaf spot diseases on common privet leaves observed at the end of vegetation period, whereas premature defoliation took place from June to October. Despite the occurrences of numerous leaf spot diseases on common privet leaves (in both years from May to October) neither seedlings’ defoliation nor their growth inhibition were observed and therefore any considerable decrease in their decorative values or their disqualification as commercial material were stated.