Mostoviak I. Agroecological substantiation of control of dominant pests number of grain ear-forming crops in the Central Forest-Steppe of Ukraine

Based on the results of many years of comprehensive research and their generalization, an agroecological substantiation of the control of the number of harmful species of organisms in the agrocenoses of grain ear-forming crops in Central Forest-Steppe of Ukraine has been developed. The main factors of destabilization of phytosanitary condition of grain crops sowings, which consist in high plowing of the territory, violation of scientifically substantiated structure of sowing areas, cultivation of varieties of intensive and semi-intensive type with high ability to accumulate phytopathogenic mycobiota and significant pesticide load. It was determined that in 58% of the surveyed crops the number of harmful organisms with exceeding the economic threshold of harmfulness was detected, which determines the phytosanitary condition as ecologically dangerous. Exceedance of the level of ETH (economic threshold of harmfulness) of weeds in 2.0-3.3 times, dominant diseases such as root rot in 2.8–4.0, powdery mildew of wheat - in 6.3–8.2 and varieties of barley spots - in 2.5 times indicates biological pollution and increased environmental risks in agroecosystems. Ecologically safe systems of harmful organisms control which provide high economic (increase of productivity by 19-25%), ecological (decrease in norms of introduction of herbicides by 17-33%) and economic (profit to 8574 UAH/hectare, profitability 60-63%) efficiency are developed.