Monitoring the spread of root roots of spring barley in the Eastern part of the Forest Steppe of Ukraine

Abstract

Barley is one of the main grain crops in Ukraine and is noted for one of the lowest production costs. However, the actual yield of barley still remains significantly lower than its potential. One of the main factors limiting the production of high gross grain yields and deteriorating its quality is the significant damage to the crop by fungal pathogens, primarily root rot. The monitoring of the phytosanitary condition of spring barley crops in the Eastern Forest-Steppe of Ukraine in 2018–2025 showed that the dominant pathogen of root rot is the fungus Bipolaris sorokiniana Shoem. (60 % of the total specific weight of pathogens), while fungi of the genus Fusarium account
for 40 %. Intensive growth and abundant formation of conidia of B. sorokiniana was noted at air temperatures
of +22+28 °C and soil moisture of 80 % of the full moisture capacity. The incubation period of the disease
was 6–8 days. For fungi of the genus Fusarium, the optimal conditions for development were at air temperatures
of +22+26 °C and soil humidity of more than 40 %. It was found that an increase in the average daily temperature by +2.4+4.5 °C and a decrease in precipitation to 60–74 % increased the intensity of root rot development: in the tillering phase from 5.5 to 17.9 %, in the earing phase from 14.5 to 44.4 %, in the waxy grain ripeness phase
from 31.8 to 57.9 %. Screening of varieties for resistance to root rots showed that the highest prevalence of B. sorokiniana was found in the Agrariy variety (70 %), in the Allegro, Kozvan and Modern varieties from 50 to 67 %. The highest level of infection by fungi of the genus Fusarium was noted in the Allegro variety – up to 50 %. Determining the species composition of pathogens, biological features of their development in different varieties allows for effective monitoring of disease development and planning timely protective measures for spring barley crops. The creation and widespread introduction of resistant barley varieties into production is a particularly urgent task, since the yield when growing such varieties can be tens of times higher compared to the use of only chemical plant protection products. Therefore, for effective protection of spring barley from root rots, it is advisable to introduce resistant varieties into production. This will contribute to the preservation of the harvest, improvement of the phytosanitary condition of agrocenoses due to the reduction of the frequency and rates of pesticide use, as well as the reduction of environmental pollution.