First report of Stemphylium vesicarium on chilli pepper in Italy.
In 2014, during a survey of fields of chilli pepper, grey leaf spot (GLS) symptoms were observed on leaves in two different Italian areas, Rieti (central Italy) and Cosenza (southern Italy). Diseased leaves were characterised by numerous tiny round spots (0.5 to 2.5 mm diameter, average 1.3 mm) that were white to grey with a sunken centre and brown edge, resulting in premature defoliation. No other part of the plant was affected. The varieties 'Fatalii White' (Capsicum chinense) and 'Diavolicchio Calabrese' (C. annum) were the most susceptible in central and southern Italy, respectively. In both locations disease incidence on the two chilli pepper varieties was >40%. Based on morphological characteristics, molecular data (sequence analysis of the internal transcribed spacer and glyceraldehyde 3-phosphate dehydrogenase gene) and pathogenicity tests, the causal agent was identified as S. vesicarium. In Italy, S. vesicarium has been reported as the causal agent of leaf spots on tomato and wilting and root rot on radish sprouts. This is thought to be the first report of S. vesicarium on chilli pepper in Italy.