Oleksiyenko I. Spatial and temporal distribution of frosts in Ukraine and their impact on fruit crops

Dissertation is devoted to the study of patterns of spatial and temporal distribution of frosts in Ukraine and assessment of the frosts danger of the country with respect to fruit crops. For the first time in Ukraine conducted a comprehensive study of spatial and temporal variability of frost and evaluation of the frosts danger of the country with respect to fruit crops, particularly in the last two decades. The analysis of the current state of research on the problems of studying the frost, which considerably extends the information on their occurrence, climatological characteristics, aspects of agro-climatic impact on agricultural production, forecasting and development of methods of struggle against them in Ukraine and in the world. On the basis of empirical meteorological information and software tools are defined modern climatological characteristics of dates last spring and first autumn frosts on the soil surface and in the air and the duration of the frost-free period. The change in these characteristics as compared with the standard rate of climate in the last decade, compared to the previous one. For the first time the classification of synoptic processes leading to the last spring and first autumn frosts in Ukraine using the V. F. Martazinova's method of "standard". It is based on statistical modeling of the nature and the tightness depending multiyear dates of the first and last frost from physical and geographical conditions of the characteristics of the territory. It was found that a statistically significant effect on the characteristics of frost is considered the geographical latitude and altitude. It was determined that the duration of the frost-free period on the soil surface modeled better than in the air. With the help of graph-analytical method of A. Lebedev, determine the likelihood of last spring and first autumn frosts on the soil surface and in the air, which can be used in modern agro-meteorological practice, including for the purpose of the main characteristics of the climate forecast frost. Determined frequency and patterns of spatial distribution of frosts of varying intensity in the flowering phase pome fruits (apple, pear) and stone fruit (cherries, cherry, plum, apricot, peach) crops. The analysis of minimum temperature for each date of freezing is determined that, in most cases 70 % , the intensity of the latter and the first frost in the air is small (up to -2°C). Investigated recurrence of frosts of varying intensity in the flowering stage of basic zoned fruit pome and stone cultures. It was determined that most of freezing damage to flowers or ovaries of fruit crops is in the north and the west of the country. A specialized division of the territory of Ukraine concerning the frosts danger conditions for fruit crops, which can be used to meet the challenges of conducting science-based agricultural production, such as gardening is conducted on the basis of cluster analysis.