Khodakivs'ka J. Economic and biological estimation of the plum cultivars (the elder trees) under the cjnditions of the Ukraine's Lisosteppe and Polissya

Objects of the researches are - biological and physiological peculiarities of pollen grains and stomas closing cells, the ploidity level and pear cultivars signs favourable for economy. Purpose is the agrobiological estimation of the L'viv Experimental Station of Hortieculture (ESH) and Institute of Horticulture of Ukrainian Academy of Agrarian Sciences (IH UAAS) pear cultivars (15-20 year trees) in the conditions of the Northern Lisosteppe and Southern Polissya as well as the selection of competitive cvs favorable for the intensive horticulture in farms of different property forms in the mentioned zones. Methods are field, laboratory, comparative and generalizing with the use of modern computer programmes for the variation statistics data processing. Novelty the dissertant has established that the L'viv ESH and IN UAAS pear cvs are able to form fruits of high marketable and taste qualities in regions with moderate effective temperature amounts the mentioned zones belonging to them on the level ofthecultivars created in southern regions. The high tolerance of the researched cvs to the most harmful diseases has been confirmed that insures the possibility of growing ecologically pure production practically without using fungicides. At the same time the increased assimilation ability of the leaf apparatus contributes into those cultivars winter - hardiness rise. The author has determined the biological potential of /their yield resistance to fungous diseases droughtand frost - resistance, marketability and quality of fruits, content of main organically and biologically active substances in them. For the first time about pear the dependence between pollen grain size and shape, on the one hand, and chloroplasts amount in the leaf epidermis stomas closing cells, the cultivar ploidity and pollen fertility, on the other hend, has been detected as well as the high degree of the correlation dependence between the stomas size and amount per the leaf surface unit and level of drought resistance, leaf photosynthetical activity and yield. Practical results. The dissertant has confirmed the ability of creating pear intense farm and amateur orchards on the basis of the L'viv breeding cvs as well as of growing ecologically pure production in the Ukraine's Lisosteppe and Polissya. Theoretical results. The possibility has been determined of using a number of express - methods and test signs in the scientific practice on the basis of cyto-genetical and morphological investigations associated with the pollen ploidity and fertility, plant winter - hardiness and drought -resistance. The results obtained are applied in production and research activity. Branch is agriculture.