Application of bacillus subtillis ch13 in the control of damping off disease in tobacco seedlings

Bacillus subtillis Ch13 is an active ammonifying bacteria who plays a main role in nitrogen cycling. But, it has multifunctional properties that, beside the stimulating, has the fungicidal effect on plants, too. It is a base of a microbiological product Exstrasol  which is used for examination. Modern tobacco production follows the ecological principles of sustainable agricultural production and supports the use of environment-friendly products, especially the use of biological products in the control of tobacco pathogens. The aim of this research is to determine the possibilities for application of this microbiological product in protection of tobacco seedlings from damping off disease. Investigations were performed in biological laboratory by artificial inoculation with the diseasecausing agents - Rhizoctonia solani and Pythium debarianum. Investigations of disease were also made in conditions of natural infection. It was determined that the application of B. subtillis Ch13 reduces the intensity of disease attack.  The percentage of infected area is lower in the variant where treatment is included. The best results in artificial inoculation with R. solani are obtained when soil treated with 1% is planted with seed treated with 10%  Extrasol. In P. debarianum, the best result was achieved with seed treated with 10 and 20% Extrasol. The best results in natural infection are achieved in seed treated with 10% Extrasol. Additional treatment of soil when the seed was treated with this product had a negative effect. The microbiological product Extrasol has good prospects for its use in tobacco control from damping off disease.