## 4 Discussion  
Sugar beet diseases caused by Rhizotonic have been known for more than a century. However, despite many studies, the economic losses of the crop yield have reached up to 2% in the USA [32]. The loss of the production of sugar beets caused by _R Rhizotonic solani_ AG 2-2 can reach, in some cases, more than 25% in the United States [33]. The conditions of _R. solani_ growth have been studied since it was reported as the most widespread and hazardous crop pathogen. Attention to growth conditions has been primarily associated with the study of the pathways to suppress pathogens and prevent plant diseases [34]. Different approaches have been used to control this phytopathogenic fungus to protect sugar beets and increase its yield. The strategies were based on the development of resistant varieties of beets [33], application of fungicides [13], and treatment with bacterial strains [1] or some organic compounds [5]. However, these possess some drawbacks. For example, Rhizotonic-resistant varieties lose 10-15% of their productivity [33], or they are not sufficiently adapted to the climate [6]. The application of chemicals causes the development of resistance to fungicides and leads to hazardous contamination of the environment [12]. Herein, a comprehensive approach based on thermodynamic calculations was suggested to evaluate a general view of the conditions that promote and suppress _R. solani_. This background was used to create conditions to control phytopathogenic _R. solani_. The approach suggested in the study to control _R. solani_ AG 2-2 IIIB via abiotic and biotic factors corresponds to the data in literature. However, the available data show that the investiga  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Strains** & **Indirect Interaction** & **Direct Interaction** \\ \hline A.1 & \(-\)\({}^{1}\) & \(-\)\({}^{1}\) & \(-\) \\ A.2 & \(+\)\({}^{2}\) & \(+\)\({}^{2}\) & \(+\) \\ A.3 & \(-\)\({}^{1}\) & \(-\)\({}^{1}\) \\ A.4 & \(++\)\({}^{4}\) & \(++\)\({}^{1}\) \\ A.5 & \(++\)\({}^{1}\) & \(tion of growth conditions was conducted sporadically, without the use of a generalized background. The generalized patterns affecting _R. solani_ AG 2-2 IIIB were shown. Based on thermodynamic calculations, it was found that unfavorable growth conditions can be created via both pathways. The first one is the application of abiotic factors (pH and redox buffers, presence or absence of O\({}_{2}\)). The second pathway is to use biotic factors such as microbial communities to create the appropriate conditions not only to inhibit _R. solani_ AG 2-2 IIIB growth, but also to cause the death of mycelium. The value of pH is one of the important factors affecting the activity of Rhizoctonia and pathogenicity [35; 36]. A wide variation of pH (6.0-8.0) was shown for optimum growth and scleroia production [36]. Other reported data revealed the optimum growth of fungus in the pH range 5.5-7.0 [35]. The absence of oxygen, together with low redox potential, is another important condition to suppress _R. solani_. Anaerobic soil disinfection implemented via the addition of easily degradable organics with water was shown to be effective in the control of a wide range of plant pathogens, including _R. solani_[37]. The application of microorganisms, conducted in our research, was shown to be an effective and up-to-date approach to control _R. solani_ AG 2-2 IIIB. It is one of the most promising ways to provide the suppression of the fungus as well as to prevent environmental pollution. Moreover, some microbial strains such as _Bacillus_ sp. [33] and yeasts (_Candida valida, Rhodotorula glutinis_, and _Trichosporan asaiti_) [38] described in literature were shown not only to suppress _Rtizoctonia solani_, but also to increase the yield of sugar beets. _Bacillus amyloliquefaciens_ SB14 strain was shown to decrease diseases of sugar beet caused by _R. solani_ AG-4 and _R. solani_ AG 2-2 [9; 39].