Influence of climatic conditions on infection of sunflower lines by phoma black stem

The purpose of the research was to analyze three year observations (2018–2020) for climate changes effect on infection breeding sunflower lines (Helianthus annuus L.) by a Phoma black stem pathogen Plenodomus lindquistii (Frezzi) Gruyter, Aveskamp & Verkley in central zone Krasnodar region. disease monitored fields V.S. Pustovoit All-Russian Research Institute Oil Crops, Krasnodar. Analysis climatic factors years resulted that heavy rainfalls (119.2?134.6 mm) exceeding multi-year averages (60.0 two times and optimal average daily temperature 23.0?26.4 ?С July are favorable second half summer, phase flowering – maturing. In 2018, moisture deficit June (11.0 August (6.8 factor suppressing viability an infectious matter fungus led low frequency (in 20.3%). 2019 2020, prevalence (P) development (R) were equal 23.3?29.9% 21.4?28.1%, respectively. A line L 107 demonstrated stable resistance during years: amount infected plants within 5.7?8.3%, 3.8?8.3% at level 1–2 points. susceptible 116 selected (P: 47.5?62.8%, R: 38.0?40.0%). Among studied lines, sample VK 900 most weather conditions year: varied 21.1?45.5% 1?3