INFLUENCE OF AGROMETEROLOGICAL CONDITIONS ON THE SPREAD OF DOWNY AND REAL POWDERY MILDEW ON HOP PLANTATIONS IN THE CHUVASH REPUBLIC
The article presents the monitoring data conducted in 2019, aimed at identifying the causes of the spread of diseases of ordinary hops: downy and real powdery mildew - in the hoppers of the Chuvash Republic. The signs of the appearance of phytopathogens, as well as the conditions for their mass distribution, and the influence of weather conditions on them were investigated. Possible disease control measures were analyzed, recommendations were presented on determining the degree of hop damage by these diseases. Observations of the causes of the spread of phytopathogens have shown that their appearance depends on both significant changes in daily average temperatures and the degree of humidity - all this creates favorable conditions for the development of diseases. In early spring, the number of spike shoots on hop plantations was 6.0%, and by mid-May it was up to 10-12%. On old-aged hoppers it reached 15% and in some households - up to 20-25%. Damage of ordinary hop leaves at hop producing enterprises in the Urmarsky, Tsivilsky, Vurnarsky and Yadrinsky districts reached 3.0 - 3.5 points (average and more than the average value), and there were also small lesions where the damage reached 4.0 points (strong power). By the phase of technical ripeness, separate flakes of the formed cones rusted, their shape and elasticity were lost. The defeat of hop cones at the enterprises of the Chuvash Republic reached 2 points, in some cases - up to 3.0-3.5 points and higher. The development of the fungus was influenced by the established favorable weather conditions, the presence of last year's foci of phytopathogens and non-observance of the optimal terms for hops harvesting. In the conditions of the Chuvash Republic, early varieties with a growing period of up to 100 days must be harvested in late August, early ripe and mid-ripening in early September. By observing the harvesting terms, it is possible to maintain commercial quality and biochemical parameters of hop cones. In vivo, the infectious spread of powdery mildew was significant. The disease settled in the wild thickets of hops, in household plots and gadrens. Therefore, such areas within a radius of 1.5-2.0 km should be uprooted. Timely detection and localization of foci of diseases made it possible to prevent their spread and control the process, and timely protective measures made it possible to reduce economic damage and get a crop of hop cones an average of 16.8 c / ha in the republic.