Avaliação da mancha preta dos citros em diferentes variedades de laranjeira doce

Abstract

The citrus black spot - CBS (Guignardia citricarpa Kiely) has been responsible for great losses in Brazil, where all commercial varieties of sweet orange are susceptible. Given the economic losses that this disease causes to the brazilian citrus industry, this study aimed to evaluate the susceptibility of sweet orange varieties with late harvest to CBS. A total of 36 varieties were evaluated in Cordeirópolis city, and 35 located at Conchal city, in two years (2007 and 2008), both in São Paulo State, Brazil, in randomized block design assays with three replications. By using a diagrammatic scale specific to the CBS, the severity of CBS was quantified between the months from June to November (2007 and 2008), data was used to calculate the area under disease progress curve. All varieties were susceptible to CBS, however Imperial and Valência Pálida Israel were less susceptible than the others at both locations.