Anthracnose is a dangerous bean disease

Abstract

Anthracnose causes the loss of seedlings, deterioration of the marketable and seed qualities of seeds, and a decrease in yield. Bean plants are affected by anthracnose throughout the growing season, especially during the period of bean formation. Angular, brown or dark brown spots form on the leaves of adult plants. In dry weather, the affected tissue falls out, resulting in holes. Infected beans develop wrinkled seeds covered with brownish-dark spots. If anthracnose infection occurs during the early stages of bean growth and development, we can expect 100 % loss of seed yield. The pathogen exhibits wide physiological variability, which can significantly compromise the resistance of commercial bean varieties. It should be noted that in susceptible and resistant varieties, the speed with which the pathogen will spread through plant tissues will differ. Cells of resistant tissues are able to localize the pathogen within their limits, which is manifested in a decrease in the intensity of anthracnose development. The high variability of the pathogen indicates the complexity of controlling the development of anthracnose and the importance of conducting research to identify new resistance genes to this pathogen. Studies to assess the resistance of bean varieties were carried out in the experimental fields of the State Enterprise “Elitne” of the V. Ya. Yuryev Institute of Plant Production of the NAAS using generally accepted methods. Four bean varieties were found to be most resistant to the anthracnose pathogen: Sombrero, Perlyna, Veselka, and Horoz. According to the results of three-year studies, no symptoms of the disease were recorded on them. Given the high variability of the pathogen and the presence of a large number of pathogen races, we can only speak of the high resistance of these varieties to the pathogen races that were presented in the 2019-2021 research years. The bean varieties Nespovanka, Dokuchaevskaya, and Galaktika were not affected by anthracnose in 2019 and 2020, however, they showed minor disease development in 2021. The degree of anthracnose development on bean plants was minor and corresponded to 1 point on the damage scale. No symptoms of anthracnose were detected on the Pervomaiska variety in 2019, but were recorded in 2020 and 2021. The bean plant damage score was 1 in 2020 and 2 in 2021. However, only 10 % of the plants showed signs of disease. The Nadiya variety was not affected by anthracnose in 2020 and 2021. A minor percentage of damage was recorded in 2019 at 8 %. The damage score was 2. The prevalence of anthracnose was 10,0 %. In 2020, no symptoms of disease development were observed on the Gothic variety. At the same time, in 2019 and 2021, the development of anthracnose on the variety was 12,0 % with a prevalence of 40,0 and 50,0 %, respectively.