A new danger for hop plants

Goal. To scientifically substantiate the ecological and biological features of the development of gray mold and to establish the patterns of influence of various methods of gray mold control on hops. Methods. Field — combined with visual observations and records; calculation and comparison — to determine the effectiveness of measures; laboratory to determine the content of biochemical components of cones; mathematical and statistical to identify the parameters of quantitative variability using dispersion and correlation-regression analysis to assess the reliability of the obtained results. Results. In 2021—2023, monitoring and phytosanitary diagnostics of gray mold development patterns in the hop agrocenosis depending on climatic factors were carried out, and the level of harmfulness under the influence of various schemes and methods of regulating its prevalence was determined. The calculation of the effectiveness of methods of control and phytosanitary optimization of hops was carried out with the processing of the obtained data, the qualitative and quantitative indicators of the harvest were determined. It has been proven that mechanical damage contributes to damage to hop plants by the pathogen Botrytis cinerea Pers. et Fr. in the phase of growth of branches before flowering, and the signs appear mainly after its flowering in July. The conidial stage of the fungus predominates on the affected hop tissues. It was established that the spread of plant damage by the causative agent of gray mold of hop plantations of Ukraine was up to 40% in Zhytomyr region, and in Khmelnytskyi, Rivne and Lviv regions — up to 25% with an intensity of up to 29%. A selected group of selection numbers that are reliably more resistant to gray mold. Conclusions. The regularities of the development of gray mold on hops depending on climatic factors have been established, as well as the level of harmfulness under the influence of various schemes and methods of regulating its prevalence, which ensure the preservation of the harvest up to 0.9 t/ ha of hop cones and 1.07% alpha-acid with a profit of up to UAH 265.000/ha.