The aim of this work was to evaluate the reaction of ten strawberry cultivars to powdery mildew (Sphaerotheca macularis f.sp. fragariae). Mother plants were transplanted into autoclaved substrate in trays with 72 cells. The disease inoculation was done by placing plants severely infested with powdery mildew in the greenhouse. The experimental design was a randomized block with split plot and four replications with ten plants. The cultivars tested were Aromas, Bürkley, Camarosa, Campinas, Dover, Milsei-Tudla, Oso Grande, Santa Clara, Sweet Charlie and Vila Nova. The disease severity was evaluated in the youngest 3 leaves during three periods: 8th, 10th and 12th week after transplanting. A rating scale was used, in which 0, 1, 2 and 3 represented 0%, 1-25%, 26-50%, and > 51% of leaf surface covered with fungal structures, respectively. The disease severity reduced with the proximity of the summer, because of higher daily average temperature. High variability to powdery mildew resistance among the cultivars was verified. 'Milsei-Tudla' showed high resistance. 'Camarosa', 'Aromas', 'Oso Grande', 'Sweet Charlie' and 'Campinas' exhibited average resistance. 'Dover' showed little resistance and 'Bürkley', 'Vila Nova' and 'Santa Clara' were highly susceptible.
Fragaria x ananassa; Sphaerotheca macularis; severity; runner plants
