Abstract

In 2015 to 2018 in the Orenburg region a comprehensive phytopathological assessment of potato varieties of different ripeness groups were carried out in order to establish the prevalence of major pathogens using the Protect and Abiga Peak fungicidies against a natural infectious background under irrigated conditions. The plot area was 140m2 (length 50 m, width 2.8 m). The accounting area was 70 m2 (length 50 m, width -1.4 m). The arrangement of options in the repetition was systematic. Out of 17 studied varieties of potato, the most susceptible varieties to Streptomyces scabies Waks. & Henr in 2015 were Lyubava (13.8 %), Agat (5.6 %), Red Scarlett (5.2%), Tarasov (5.1%), Fresco (3.0%) and Burren (2.2%), including standard varieties viz. Nevsky (12.8%) and Spiridon (5.1%). During 2015, it was also observed that the greatest defeat of tubers with stolon rot (Fusarium oxysporum Schlecht.) was found in varieties Agat (4.9%), Fresco (5.3%), Burren (8.7%), Nevsky (4.9%) and Spiridon (3.0%). Eight of the 17 varieties studied namely Tarasov, Sante, Impala, Sheri, Zakhar, Itzil, Cavalier and Bracelet were resistant to Fusarium oxysporum Schlecht and Streptomyces scabies Waks. & Henr. When using fungicides (Abiga Peak and Protect), plant damage was practically not observed. Cavalier and Zakhar potato varieties which gave high production (40 t/ha) and resistant to the studied pathogens, have been identified and recommended for cultivation under irrigated conditions of the Orenburg region. These two varieties (Cavalier and Zakhar) were also recommended to be used in the selection process as indicators of high productivity and low incidence of Streptomyces scabies Waks & Henr and Fusarium oxysporum Schlecht.