First report of the natural occurrence of <i>Pyrenopeziza brassicae</i> Sutton et Rawlinson, the apothecial state of <i>Cylindrosporium concentricum</i> Greville, in brassica crops in New Zealand

Abstract

Summary In May 1978 a severe epidemic oflight leaf spot occurred in crops of cauliflowers ( Brassica oleracea L. var. botrytis L.), cabbages ( B. oleracea L. var. capitata L.), and sprouting broccoli ( B. oleracea L. var. italica Plenck) in parts of the Pukekohe district. Conidia produced on lesions associated with the disease were typical of those of Cylindrosporium concentricum Greville, previously reported to be the causal pathogen. Three months later numerous small black apothecia were found on decaying petioles, veins, and occasionally lamina tissue of fallen leaves from these crops. When vegetable brassica seedlings were inoculated with ascospore suspensions obtained from these apothecia typical symptoms oflight leaf spot developed 11‐14 days later. The apothecia were identified as those of Pyrenopeziza brassicae Sutton et Rawlinson. This is the first record of the natural occurrence of the teleomorph (perfect state) of the species in New Zealand.