Formation of phytopathogenic fond in agrocenoses of cereals of the right-bank Forest-steppe of Ukraine

Abstract

Тhe features of the formation of phytopathogenic fond of micromycetes, pathogens of cereal diseases of the right-bank Forest-steppe of Ukraine for 2004– 2019 are analyzed. The leading place in the phytopathogenic complex is occupied by micromycetes, among which the pathogens of root rot and powdery mildew dominate. The area of crops affected by these diseases is 32.5–75.0%, and in some years reaches to 100%, the spread of diseases — 4.2–19.8%, the development of diseases — 1.6–14.0%. In addition, leaf septoria and pyrenophorosis predominate in agrocenoses of winter wheat, at spring wheat — dark brown spotting; spring barley — spotting and rhynchosporium. Olive mold and fusariosis dominate among the diseases of the head. During the study period, a significant development of winter wheat pyrenophorosis was noted — 5.1–16.8% (max 35%), brown leaf rust spread on spring wheat — 4.6–24.4% (max 45%) and spread of spotting of spring barley — up to 50% (max 100%). Exceeding the threshold of harmfulness of root rot (in 2.8–4.0 times), powdery mildew of wheat (in 6.3– 8.2 times) and spotting of barley (in 2.5 times) leads to excessive use of fungicides and causes increased environmental risks in agrocenoses, chemical and biological pollution of agroecosystems, which significantly affects the quality and safety of products.