Biological protection of the main cereals against fungal specific diseases.

Our field experiments showed that the use of Czech biopreparations (Supresivit, Ibefungin and Polyversum) based on the following microorganisms: Trichoderma harzianum, Bacillus subtilts and Pythium oligandrum applied as the seed treatment, the spray on the plants and like the mixture with mineral fertilizers (NPK, ammonium sulphate) lead namely after the seed-treatment and after the application as the mixture with mineral fertilizers to the increasing of the yield about 3-5 % (spring barley, winter wheat). This increasing was given by depression of soil-borne phytopathogenic fungi of the genera: Fusarium, Drechslera (Helminthosporium), Pseudocercosporella (Tapesia), Gaeumannomyces, and partially Rhynchosporium. The number of the fungi on plant rests were also influenced. No effect was observed on smuts and rusts. The smuts needed the seed-treatment with Vitavax (carboxim, thiram, imazalil) which didn't influence the biological treatment with biopreparations. The doses of biopreparations were following: the mixture with mineral fertilizer - 0.1 g of biopreparation/ kg of mineral fertilizer, the seed treatment - 0.1 g of biopreparation/1 kg of the seed and in the spray 0.1 g of biopreparation/1 litre of distilled water. Biological biopreparations will be usefull probably also in the future because they don't create the harmfull residues. The impact of the biopreparations under different ways of soil tillage (conventional variant with ploughing, variants with different plant residues and variants without ploughing) was studied as well. The influence of different soil preparation on composition of the soil mycoflora and the influence on quantity of the pathogenic genera Fusarium, Drechslera and others was observed. Quantity of named genera was negatively influenced while yield and health status of the plants were influenced positively.