ABSTRACT
Peach rust, caused by Tranzschelia discolor, is the main foliar disease of the crop. The aim of this study was to evaluate and compare the intensity of the disease in a set of eleven peach cultivars (Aurora 1, Chimarrita, Chiripá, Coral, Eldorado, Granada, Leonense, Maciel, Marli, Premier and Vanguarda) grown in orchards handled following the “norms for integrated peach production”, at Lapa- PR, Brazil, between November and April. The experiment was conducted in randomized blocks with three plants of each cultivar in a block. The central plant of each cultivar was evaluated the incidence and severity of peach rust on leaves of eight mixed branches previously marked, every 15 days,. The incidence of peach rust on the leaves, in all cultivars, ranged from 25.4% (Eldorado) to 82.6% (Chimarrita) in the first season and from15.3% (Eldorado) to 49.3% (Granada) in the second season. The logistic model was fitted to the data of the incidence progress over time. The estimated values of initial inoculum and rate of disease progress did not differ among cultivars. The severity was low (<1%), for most cultivars in two seasons and the area under severity progress curve of Chimarrita and Granada cultivars differed from the others only in the first season. There was no defoliation caused by the disease. The Eldorado had lower rust intensity and Chimarrita and Granada greater intensity among cultivars.
Prunus persica; Tranzschelia discolor; incidence; severity
