Object: formation of winter hardiness in winter crops and varieties, methodology of assessment of frost- and winter hardiness of varieties, monitoring and diagnostics of crop condition, prediction of overwintering and yield capacity of cereals. Aim: theoretical and methodological rationale of the determination system of frost- and winter hardiness of winter cereal varieties, monitoring of crop condition, formation and prediction of yield capacity and , on this basis, to develop an optimal structure of sown areas to stabilize grain production. Methods: general scientific, field, growing, measuring weight, laboratory, biochemical, statistical methods. Novelty: for the first time in Ukraine, the scientific problem of winter cereal adaptation to cultivation conditions through was solved by developing methodological principles of winter hardiness determination, systematization of methods for crop monitoring and grain yield prediction. Biochemical peculiarities of winter hardiness of winter cereals were determined; differences in their carbohydrate and protein-nucleic acid metabolism were revealed. This became a prerequisite for establishing the nature of their differentiation in terms of resistance. Methods for screening of varieties and species for frost hardiness and for formation of trait collections were rationalized and developed. On the basis of the low temperature tolerance ranges established for winter crop varieties, correlations between their resistance and yield capacity, species and varieties that combine high winter hardiness and yield capacity were identified. Methods for determination of frost hardiness and diagnostics of plant viability in winter crops and for prediction of yield capacity were improved. The system for determination of winter hardiness by forming a uniform scale of hardiness for winter cereals was further developed. Results: The system of monitoring of winter crop condition, screening of varieties for frost hardiness was developed. Two trait collections - of soft winter wheat and of winter triticale - were formed. An optimal structure of winter crop sown areas was rationalized. The methods developed for determination of frost hardiness of varieties and chlorophyll content in winter wheat leaves, for which an inventor's certificate and patent for utility model were received, increase the efficiency of assessment of resistance and viability of varieties. Implementation Degree: State standard of Ukraine 4749: 2007 "Winter Wheat. A Method of Determination of Variety Frost Hardiness" was developed and implemented for screening of winter wheat varieties, and the most suitable for use in Ukraine varieties were identified. On the basis of accessions from the trait collections, 10 winter wheat varieties with the winter hardiness of 7-8 points and a winter triticale variety were co-authored and introduced. The scientific support of winter crop cultivation was implenented in Kharkiv, Poltava and Sumy regions, on the total area of over 450,000 ha. Implementation Scope: research institutions of NAAS and the Ministry of Agrarian Policy and Food of Ukraine, higher educational establishments, and agricultural units of agro-industrial complex of Ukraine.
