Nikishicheva K. Complexes of phytonematodes in agrocenoses of the winter wheat in diverse soil and climatic zones, and measures of regulation of their density.

Object of study: phytonematodes, winter wheat. Purpose of study: investigation of specie composition and structure of phytonematodes complex in agrocenoses of the winter wheat in different soil and climatic zones, determining the dynamics factors of the nematodes populations density, determining of plant parasitic nematodes nocuity and search for ecologically safety methods for their population's regulation. Methods of study: field, laboratory, statistical. Theoretical results: it has been established the presence of stable nematodes complex in agrocenoses of winter wheat on the base of species composition study, ecological and taxonometric structure of nematodes groups. It has been developed the complex approach to the study of agricultural cultures, based on the determining the dynamics factors of the phytonematodes population density and the state of host-plants, serving of base for planning the protective measures. Practical results: Regressive model of dependence of the plants state and yield on population density of parasitic nematodes, and conditions for the culture vegetation shall be used for the yielding losses predicting. Using the complex seed disinfectant treatment gives a possibility of important decrease of the parasitic nematodes density and keeping 15 - 17 % of yield without additional material costs and pesticide load. Some varieties resistant to nematodes (Myronivs'ka 27, Kryzhynka, Don 85) shall be utilized as resistancy gene donors for selection of the national, resistant to nematodes, varieties. Novelty: For the first time it has been studied the species composition of nematodes groups in agrocenoses of winter wheat in various zones of its growing and it has been proved a presence of the stable complex of phytonematodes. It was been studied the dynamics of the parasitic nematodes density, nature and rate of their influence on the plants of winter wheat, evoking 15 - 17 % of the yield losses. The thresholds of nematodes nocuity were been determined. First it has been proved a sufficiently high antinematodes efficiency of the three contemporary disinfectants for the winter wheat seed treatment. There were been revealed 3 varieties relatively resistant to nematodes (Myronivs'ka 27, Kryzhynka, Don 85). Rate of introduction: the tests results were been checked at Mykolaiv Institute of Agroindustrial Production in Mykolaiv region, at the 20 hectares area and shall be used at the farms with different forms of ownership. Sphere of utilization: agriculture.