Sakhnenko V. Agroecological Substantiation and Forecasting of the Dynamics of the Insect-Phytophagus Population in Winter Wheat Protection Systems in the Forest-Steppe of Ukraine

The thesis substantiates the improved technology of protecting winter wheat from the complex of harmful phytophagous insect species in protection systems using development and reproduction monitoring, as well as the distribution of phytophagous complex in new field crop rotations when growing winter wheat, which will increase production in the forest-steppe of Ukraine. The analysis of the long-term dynamics of the number of pests of winter wheat in the conditions of the Forest-Steppe of Ukraine demonstrates the modern features of the formation of phytophagous groups by the stages of organogenesis of cultivated plants and the formation of crop yields. In 2002–2018 in the Forest-Steppe of Ukraine, insect species were found and the structure of the entomocomplex was clarified: soil, leaf-eating, internal sturgeon, sucking harmful insect species, contributed to a decrease in winter wheat productivity by 25–37 %, density of productive stalk growth by 8–14 %, the spread of insect pathogens to 24 % of the surveyed areas, as well as a decrease in winter hardiness and grain quality by 21 and 36 %, respectively. At the same time, marginal spraying of wheat shoots with a winter insecticide with the content of the active ingredient imidocloprid, 0.15 l/ha with a urea-ammonia mixture (CAM, 32 %), and reliably reducing the number of adult pests. Continuous spraying of crops with insecticides with etc. dimevit (1 l/ha) with CAS solution, 32 %, 10 l/ha was also found to reduce the number of larvae of swedish, black wheat flies and other phytophagous insects compared to the control. The high efficiency of modern protective measures against the complex of harmful species of insect phytophages on the variants with the use of prediction models for the reproduction of the complex of winter wheat pests has been noted. In particular, tank mixtures with the use of active substances flutriafol and Tiabendazole, carbendazimiv with the addition of active substances – imidacloprid or dimetoate or chlorpyrifos and cypermethrin, or lambda-cyhalothrin. This helps to reduce the number of the complex of harmful insect species and does not exert a negative impact on beneficial species of organisms, and also increases the effectiveness of the protective action by 27.3–35.8 % of modern preparations and allows controlling up to 86.5 % of harmful insect species in the structures of the agrocenosis compared with conventional technologies.