The effect of biological and chemical preparations on limiting the development of rhynchosporiosis on winter barley

Abstract

Goal. To determine the effectiveness of biological preparations and chemical fungicides against the causative agent of rhynchosporiasis on winter barley crops in the conditions of the Western Forest Steppe. Methods. Field — to establish the dynamics of development of rhynchosporiosis of winter barley; during the years of research; laboratory — to identify pathogens, and calculate technical efficiency of biological and chemical preparations; mathematical and statistical — to determine the reliability of the obtained data. Results. It was established that in 2021–2022 rhynchosporiosis (the causative agent is Rhynchosporium graminicola Heinsen) became the most widespread among all fungal diseases of winter barley. Based on the results of two-year studies, recommendations are given for the protection of winter barley against this disease. The technical efficiency of the used biological and chemical preparations against rhynchosporiasis on the Deviatyi Val variety in the phase of milk ripeness was on average: aviator Xpro 225 EC, k.e. (0.8 l/ha) — 86.0%; bactophyte (2.0 l/ha) — 49.0%; trichodermin SK (2.0 l/ha) — 52.3%; trichodermin-93 (2.0 l/ha) — 53.1%; bactophyte (2.0 l/ha) + trichodermin SK (2.0 l/ha) — 57.4%; bactophyte (2.0 l/ha) + + trichodermin-93 (2.0 l/ha) — 54.4%. It was proven that the use of chemical and biological preparations significantly reduced the development of diseases of fungal etiology and contributed to the growth of crop productivity. The highest yield, namely 4.2 t/ha, was obtained in the variant where the aviator Xpro 225 EC was used, k.e. (0.8 l/ha). In the case of the use of biological preparations, this indicator decreased slightly and amounted to 3.8–4.1 t/ha. Conclusions. In the conditions of the Western Forest Steppe, to protect winter barley of the Deviatyi Val variety against rhynchosporiosis, it is better to use the fungicide aviator Xpro (0.8 l/ha) and biological preparations bactophyte (2.0 l/ha) + + trichodermin SK (2.0 l/ha). The technical efficiency of biological preparations against the causative agent Rhynchosporium graminicola Heinsen in the phase of milk ripeness was in the range of 49.0–57.4%, and that of chemical preparations reached 86.0%. Application of the drug aviator Xpro 225 EC, k.e. (0.8 l/ha) increased the yield of winter barley by 1.5 t/ha.