FIELD EFFICACY OF PLANT PROTECTION TREATMENTS AGAINST APPLE SCAB AND POWDERY MILDEW UNDER ORCHARD CONDITIONS IN SOUTHERN ROMANIA

Abstract

Apple scab and powdery mildew are major fungal diseases affecting apple orchards and require effective protection strategies adapted to local conditions. This study evaluated selected treatments against apple scab (Venturia inaequalis) and apple powdery mildew (Podosphaera leucotricha) under field conditions in southern Romania in 2024. Disease frequency was assessed on susceptible plant organs and compared with untreated controls. Champ 77 WG and Chorus 50 WDG + Merpan 80 WDG reduced apple scab frequency on leaves by 71.43 % and 85.71 %, respectively, while both treatments completely prevented
visible fruit infection. For powdery mildew, Limocide and Topas 100 EC reduced disease frequency by 60.00 % and 80.00 % on leaves and by 78.95 % and 73.68 % on annual shoots, respectively. The results showed that treatment performance depended on the target pathogen and plant organ assessed, supporting organ-specific evaluation when selecting disease-management strategies for apple orchards.