Marytin O. Сucumbers Ascochyta and agrobiological basing of limitation of measures of its development in green-houses

The dissertation is devoted to cucumber aetiology study and agrobiological basing of limitation measures of its development. Spreading, development, mechanism and potential harmfulness of the desease that is only inherent in winter conditions of block greenhouses in which it is represented in a mixed phytopathology complex has been singled out and is dominating in it. The biological development cycle is investigated. Itis represented bu endogenous mycelium, unsexual picnidial Ascochyta cucumeris Fautr. et Roum sexual bearinj Didymella bryomoi (Pass) Rehm, which is formed episodically. The main source of the infection is damaged plant residues. It is determined that spreading and disease development is in direct dependence with hydrothermalic regime which is formed is greenhouses. Chemical disinfector of plant and cultivation constructions and thermal one reduces viability of picnidial bearing of Ascohyta pathogen on plants by 55,3 - 66,6 %. The possibility to use fungicides of 25 % bileton, 70 % topsinM, 10 % topaz spraying by plant method, their application into the greenhouse soil separately and in the form of mixture with mineral fertilijers and artificial paste preparations on their base to prevent Ascophyta stem necrosis have been cleared up as the result of the conducted investigations. One of the ways of controlling Ascophyta is the application of fungus antagonist Trichoderma harzianum Rifai. Bioagent can be used by cucumber plant spraying and in the form of paste for the therapy of stem necroses. The calculations of the economic efficiency of fungicides and fungus - antagonist in cucumber plant protection against Ascophyta showed the economic expediency of their application. Net profit was 6,52 - 8,42 hryvnas / metres2.