Distribution of pathotypes of sunflower downy mildew (Plasmopara halstedii (Farl.) Berl. et de Toni) in Hungary

Downy mildew of sunflower, caused by Plasmopara halstedii (Farl.) Berl. et de Toni, is one of the most important diseases of sunflower. There are several pathotypes of the pathogen and the number of these races is increasing rapidly. Recently, new races, such as 704 and 714 have been identified in Hungary. It is essential to regularly test the virulence pattern of this pathogen for effective resistance breeding of sunflower. Our objectives are to monitor continuously sunflower downy mildew and identify pathotypes of P. halstedii in Hungary.

Distribution of pathotypes of sunflower downy mildew (Plasmopara halstedii (Farl.) Berl. Et de Toni) in Hungary

Rita Bán1, A. Kovács2, G. Baglyas1, M. Perczel3, M. Égei1, Gy. Turóczi1, K. Körösi 1

1 Szent István University, Faculty of Agricultural and Environmental Sciences, Plant Protection Institute, H-2100 Gödöllô, Páter K. u. 1.
2 Syngenta Kft, H-1117 Budapest, Alíz u. 2.
3 PlasmoProtect Kft, H5540 Szarvas, Szabadság út 1–3.

Downy mildew of sunflower, caused by Plasmopara halstedii (Farl.) Berl. et de Toni, is one of the most important diseases of sunflower. There are several pathotypes of the pathogen and the number of these races is increasing rapidly. Recently, new races, such as 704 and 714 have been identified in Hungary. It is essential to regularly test the virulence pattern of this pathogen for effective resistance breeding of sunflower. Our objectives are to monitor continuously sunflower downy mildew and identify pathotypes of P. halstedii in Hungary.
Samples were collected from 15 different sites in Hungary in 2014. Pathotypes were determined according to the internationally standardized method for race identification. During the survey in 2014 five pathotypes, 714, 704, 700, 730 and 710, of P. halstedii were identified. According to our results pathotypes 704 and 714 were widespread on the examined sunflower hybrids. It seems that these races are spreading continuously because of the favorable weather conditions in some years as well as ineffective crop rotation and weed control. Integrated approach, including the use of resistant hybrids, crop rotation (4–5 years), effective weed control and seed treatment, therefore, is essential against sunflower downy mildew.

For full text see Növényvédelem (Plant Protection) journal vol. 52 (2016) (8): 391-396.