Zhilina T. Parasitic nematodes of potato in the East Polesje of Ukraine: spreading, harmfulness and quantity control methods

The objects of investigations: phytonematodes, potato. The purpose of investigations: to study phytonematodes kind composition of potato rhizosphere; to reveal the degree of infection in potato caused by Ditylenchus destructor and Globodera rostochiensis in private farms of Chernigov region and losses caused by these parasites; to improve plant protection means and to optimize the methods of samples selection depending on research goal. The methods of investigations: field, laboratory, statistics. Theoretical results: the kind composition of nematodes groups of potato agrocenosis is investigated for the first time. It was proved that permanent potato growing causes the specific kinds complex forming in its rhizosphere. Based on phytonematodes number dynamics studying according to ditylenchosis development phases in potato tubers the succession of parasitic and saprophyta kinds of nematodes is shown. Practical results: the character and degree of parasitic nematodes influence on potato plant have been analysed. The harmfulness levels of G. rostochiensis and their dependence on climate conditions in vegetation period and potato sort features are defined. The biological features of 7 nematodes resistant sorts are researched and the best sorts corresponding to these features are chosen: Obriji, Sednivska rannya, Chernidivska rannya, Pekyrivska, Vodogray. The novelty: For the first time it was shown that phytonematoes kind composition in potato rhizosphere includes 57 kinds, related to 49 genera, 27 families and 5 orders. Among revealed kinds the specific ones for this culture are G.rostochiensis, Longidorus elongatus, Hemicriconemoides wessoni, Macroposthonia annulata, Criconema sp. For the first time G. rostochiensis was revealed in 26 settlements and D. destructor in 96 settlements of Chernigov region. The invasion level was analysed. Te dynamics of parasitic nematodes number have been investigated during vegetation period and its dependence on climate conditions, cenosis cultivation duration and sort features of potato was studied too. Under high number of these kinds the delay of growth (36,7-45,6%),crops and market tuber reducing are observed. Sphere of utilization: agriculture, phytopathology.