Bacterial blight, caused by Xanthomonas axonopodis pv. vignicola, is a disease that has the potential to cause damage to cowpea crops. The aims of this work were to report the occurrence of such a pathogen in Roraima State, Brazil, and provide information about the reaction of cowpea cultivars to that disease. The used cultivars were BRS-Amapá, BR02-Bragança, BRS Guariba, BR17-Gurguéia, BRS Mazagão, BRS Milênio, BRS Patativa, Pitiúba, BR03-Tracuateua and Vita-7. The study was carried out in a greenhouse in a completely randomized experimental design, with four replicates, each one represented by two plants per pot. Incubation period and disease severity were evaluated at 25 days post-inoculation. The field experiment was carried out in an experimental design of randomized blocks with four blocks, each one represented by 10 plots, and each plot was sown with one cultivar. Inoculations were performed at 35 days after sowing, at the beginning of flower bud emission. Evaluation parameters consisted of incubation period, disease severity at 12, 18, 22, 27 and 29 days post-inoculation and bacterial transmissibility through seeds. The cultivars BRS Mazagão, BR 17- Gurguéia and Vita-7 presented resistance reaction to bacterial blight. No bacterial transmissibility was detected under these experimental conditions.
Vigna unguiculata; Xanthomonas axonopodis pv. vignicola; Xanthomonas campestris pv. vignicola; resistance
