The effect of weather conditions and application of mineral fertilizers on quality indicators of Callistephus chinensis (L) Nees

With the development of modern floral business, Callistephus chinensis (L.) Nees is among the top three of the most popular crops, yielding only chrysanthemum and calendula in commercial cultivation. This is one of the most widespread seasonal decorative annual flower crops, which is beautifully cultivated in open ground, pots and bouquet flowers. The researches presented in the article were conducted in order to determine the influence of weather conditions during the growing season of C. chinensis on the research sites of the educational scientific-production complex of the Sumy National Agrarian University (Northeast Forest-steppe of Ukraine) and the effectiveness of the application of various norms of complex mineral fertilizers, introduced at the planting of seedlings into open ground, on the processes of growth, flowering and other qualitative characteristics of the five varieties. During the growing season, the climatic conditions of the region of conducting research, variety characteristics, and also the variability of the parameters of height, number and diameter of C. chinensis inflorescences of the varieties 'Olenka', 'Leleka', 'Litnia Nich', 'Tsarivna' and 'Yabluneva' were influenced by variability mode of mineral nutrition. Weather conditions of vegetation have an impact on the number and size of inflorescences. According to research results, it has been established that there is a certain relationship between the weather conditions of the year and the number of inflorescences. So, the increase in the amount of precipitation during the growing season contributes to the development of the vegetative mass, but also negatively affects the formation of the number of inflorescences C. chinensis. For most varieties, the optimal conditions for the development of the generative sphere were the normal conditions for moisture of the year, and for the 'Litnia Nich' variety it was dry. The greatest increase in height when fertilizing compared to control was observed by the variety 'Tsarivna' (15.9 %), the smallest - by the variety 'Olenka' (2.0 %). The formation of inflorescences of greater diameter by the plants of the varieties 'Olenka', 'Litnia Nich' and 'Tsarivna' was observed in 2016, and by the 'Leleka' and 'Yabluneva' varieties in 2017. For most varieties in 2015, the diameter of inflorescences was the smallest. Studies have shown that weather conditions do not have a significant effect on the diameter of inflorescence, unlike mineral nutrition. The diameter of the inflorescences was the highest in comparison with the control by the variety 'Olenka' (18.3%), the smallest - by the variety 'Tsarivna' (1.1 %). The most valuable morphological and decorative features of C. chinensis plants of the five varieties under study were formed according to the norms of complex mineral fertilizers (nitroamofoska) 6.0 g/m2. The further increase of norm was not appropriate.