E. Yu. Toropova1, 2, A. E. Kudryavtsev3, G. Ya. Stetsov 4, 5, M. P. Selyuk1, 2
1Novosibirsk State Agrarian University, ul. Dobrolyubova, 160, Novosibirsk, 630039, Russian Federation
2All-Russian Research Institute of Phytopathology, ul. Institut, vl. 5, r.p. Bol’shie Vyazemy, Odintsovskii r-n, Moskovskaya obl.,143050, Russian Federation
3Altay State Agrarian University, prosp. Krasoarmeysky, 98, Barnaul, 656049, Russian Federation
4Federal Altai Scientific Center of Agrobiotechnologies, Nauchnyi gorodok, 35, Barnaul, 656910, Russian Federation
5Altay State University, prospect Lenina, 61, Barnaul, 656049, Russian Federation
Abstract. The purpose of the studies was to determine the level of population of Bipolaris sorokiniana conidia in the soil in the Kulunda zone under modern technologies and to assess the effect of agroecological factors on the phytosanitary state of the soil. The studies were conducted in 2018–2019. The soil was analyzed by the flotation method with the determination of the total number of B. Sorokinana conidia and the state of populations by the viability of resting phytopathogen’s structures. The phytosanitary state of the soil in terms of ordinary root rot pathogen conidia population was unfavourable and was up to 16.3 times higher than the biological threshold of injuriousness. The population of B. Sorokiniana conidia in the 0–10 cm layer of cultivated soils was 7.9–10.5 times higher than in the similar virgin soil horizon, which was populated at the level of or below the threshold value; the population of B. Sorokiniana conidia in the 11–20 cm layer of cultivated soils was 6.3–7.8 times higher than in the similar virgin soil horizon. The increase in the phytopathogen population in the soil was closely associated with a decrease in the total reserves of organic matter in the upper layers of cultivated soils during the cultivation period (r = -0.960 ± 0.199) and with a decrease in humus content by 48–54% (r = -0.953 ± 0.215). The biological effectiveness of phytosanitary forecrops (fallow, sunflower) in reducing the number of conidia in the soil averaged 50%. They significantly increased the proportion of conidia with signs of degradation – on average by 19.3%. According to the variance analysis results, the largest influence on the conidia abundance was exerted by the vegetation cover (crops or wild plant species), then the type of cultivation (agrocenosis or virgin soil) and sampling depth. The humus content of 77.2% depended on the type of soil development. The influence of vegetation on the value of this indicator was 4.5 times lower (17.2%).
Keywords: soil; Bipolaris sorokiniana; humus; organic matter; forecrop; factor influence.
Author Details: E. Yu. Toropova, D. Sc. (Biol.), prof., head of laboratory; A. E. Kudryavtsev, D. Sc. (Biol.), prof.; G. Ya. Stetsov, D. Sc. (Agr.), leading research fellow, prof.; M .P. Selyuk, Cand. Sc. (Biol.), research fellow (е-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.).
For citation: Toropova EYu, Kudryavtsev AE, Stetsov GYa, et al. [Population of Bipolaris sorokiniana Sacc. Shoem. in the soil in the arid Kulunda zone of Altai]. Dostizheniya nauki i tekhniki APK. 2020;34(1): 12-5. Russian. doi: 10.24411/0235-2451-2020-10102.