The intensity of disease manifestations in the agrocenosis of broad beans (Vicia faba L.) in Western Siberia

Abstract

The article presents the results of long-term observations in the agrocenosis of broad beans (Vicia faba L.) on leached chernozems in the climatic conditions of the forest-steppe of Western Siberia in order to determine the frequency and intensity of plant diseases. According to a large number of studies by both domestic and foreign experts, this crop is quite actively affected by a whole range of diseases, which causes significant damage to the harvest and quality of agricultural products. During the study, a number of diseases (common mosaic, fusariosis, spotting of various etiologies, downy mildew, etc.) were identified in broad bean crops, the intensity of development of which depended on the weather conditions of the growing season and the environmental requirements of the pathogens. It was found that in years with sufficient moisture levels, fusariosis and downy mildew predominated. The correlation coefficient between the prevalence of fusariosis wilt and HTC was 0.9 at p < 0.05. The level of development of downy mildew exceeded the harmfulness threshold (more than 40%), which was also due to the level of moisture during the growing season. It was shown that dry conditions, favorable for the growth of activity of aphids, which are carriers of common mosaic, contributed to the development of this disease (up to 53%) and an increase in the rate of infection growth. It was found that the degree of development of various types of spotting caused by a complex of pathogens (species of the genera Alternaria, Stemphylium, Cercospora) was high at all stages (from emergence to bean ripening) and in all years of the study. (development index – up to 61.6%, prevalence – 100.0%). This led to infection of seeds of the new crop up to 40% and to a decrease in their sowing qualities, which indicates the need for protective measures against these pathogens, especially in seed crops.