Epidemiology of Mycosphaerella Leaf Spot and Powdery Mildew and Agronomic Parameters of Strawberry Cultivars and Genotypes in the Highland Region of Southern Brazil

Abstract

The productivity and quality of strawberries in southern Brazil are affected by the lack of cultivars adapted to different regions and by their susceptibility to diseases. This study aims to evaluate the resistance of cultivars and genotypes to mycosphaerella leaf spot (MLS) and powdery mildew (PM) and the quantitative and qualitative fruit agronomic parameters (FAP) of strawberries in southern Brazil during the 2019/2020 and 2020/2021 growing seasons. The incidence and severity of MLS and PM were evaluated from the beginning of symptoms appearances until harvest. Cultivars and genotypes were compared based on the area under the incidence (AUIDPC) and severity (AUSDPC) disease progress curves and the quantitative and qualitative FAP. The data were subjected to analysis of variance, and multivariate analysis was performed using principal component analysis (PCA). The cultivars Irma, Bellalinda, Kiara, Jonica, and Pircinque exhibited the lowest values of AUIDPC and AUSDPC, demonstrating the highest resistance to MLS and PM. The cultivars Kiara, Jonica, and Pircinque, along with genotype FRF LAM 119.1, showed the best qualitative and quantitative FAP. However, the FRF LAM 119.1 genotype exhibited the highest values of AUIDPC and AUSDPC, indicating high susceptibility to MLS and PM. CPA data indicated that the cultivars Kiara, Jonica, and Pircinque had the highest level of resistance, which was associated with the highest total fruit yield and the best fruit quality in terms of skin color and flavor balance. Kiara, Jonica, and Pircinque proved to be good options for strawberry production in southern Brazil, combining resistance to MLS and PM with good FAP.