The Incidence Rate of White Rot (Sclerotinia sclerotiorum (Lib.) de Bary) Disease in Sunflower Cultivation Areas in Konya and Aksaray Provinces and its Pathogenic Potential

Abstract

This study was conducted between June-September 2017-2018 in sunflower cultivation areas of Konya and Aksaray to determine the incidence rate of white rot disease and its pathogenic potential and to identify the disease agent Sclerotinia spp., Surveys were carried out 11,750 decares in total from Karatay, Altınekin, Cihanbeyli, Karapınar, Kadınhanı and Çumra districts of Konya province and 3000 decares in total from Centre of Aksaray (Hırkatol and Topakkaya village) and Eskil districts of Aksaray province. In the study, it was determined that the isolates obtained from diseased plants belong to Sclerotinia sclerotiorum (Lib.) de Bary. Although the disease was not seen in the first year in Konya, the disease rate in Altınekin district was determined as 9.38% in the second year. As a result of the survey studies, the disease rate in the Center of Aksaray in 2017 and 2018, respectively, was 2.83% and 3.97%; in Eskil, while no disease was occurred in the first year, it was determined at a rate of 4.16% in 2018. In the pathogenicity tests carried out with sunflower seedlings using approximately 20% of the isolates, it was found that the disease severity of the isolates varied between 56% and 66% and the difference between the disease severity and scale values of the isolates was statistically significant (P <0.05). Aksaray / Hırkatol was found to be the most virulent isolate in the pathogenicity test.