Dermenko O. Main fungal diseases of winter triticale and their resistance sources under the conditions of Forest-step zone of Ukraine

Object - agents of fungal diseases of winter triticale. The aim - to study the complex of pathogenic fungi, infecting winter triticale under the conditions of Forest-Step zone; to characterize immunologically the selection material; to determine the sources of resistance to diseases. Methods - phytopathological, statistical. Novelty - 1) complex of plant pathogenic fungi, isolated from infected plants and seeds of winter triticale is descried (16 species of 11 genera, 7 families, 6 orders and 4 classes are isolated and determined); 2) the results of study of spreading and development of main diseases are shown - brown leaf rust, powdery mildew, leaf septoriosis, fusarioses, root rots and snow mоld; 3) races composition of brown leaf rust of winter triticale is studied, 10 races are identified; 4) it is stated, that the penetration of brown rust agent into the plant depends mainly from the number of its appresoria and morphological structure of the leaves, mostly - from the number of hydatodes; 5) possible yield losses are precised depending on development of powdery mildew and leaf septoriosis; 6) using of composite nitrogen-phosphorus-potassium fertilizers inhibits the development of leaf septoriosis. Results of the study. It is stated that development of brown leaf rust of winter triticale can reach 68,5%; powdery mildew - 28,5; leaf septoriosis - 73,6; fusarioses - 24,3; root rots - 38,5%. Spreading of snow mоld can be 67,0%. In the result of immunological estimation of sorts and lineages 27 sort-samples with complex resistance against fungal diseases are determined. Using artificial infections background 3 resistant sorts and 2 lineages against leaf septoriosis are selected. All of them can be used in hybridization as the sources of resistance for the development of new sorts. Yield losses of winter triticale from the development of powdery mildew and leaf septoriosis can be 16,9 and 23,3% respectively. The results of the study can be used in selection of new sorts and in agricultural production by the development of control measures of winter triticale against diseases. Branch - agriculture.