Peculiarities of common fennel inflorescences forming (Foeniculum vulgare Mill.) depending on the agrotechnical measures in the condition of South Ukraine

Fennel (Foeniculum vulgare Mill.) is a well-known medicinal plant. It has abundant applications in medicine and pharmacology. The article highlights the features of generative development of fennel at the following levels: sowing, one plant, one inflorescence and individual flower buds, flowers, fruits. It also specifies the duration of the main phases of generative development, the peculiarities of formation of fennel inflorescence in the arid conditions of Southern Ukraine. The research findings show that the duration of generative development of the crop is 73 days or 57% of the growing season, the productive inflorescences are central umbel and two top umbels of the first row. The article analyzes the influence of nutrition background, dates of sowing, row spacing on the seed productivity of certain compound umbels and plants in the South of Ukraine. The results of research show that the most favourable conditions for seed formation within the productive umbels and fennel plants on the dark chestnut soils in the South of Ukraine are ensured by the interaction of early spring sowing in the third decade of March, row spacing of 45 cm, nitrogen fertilizers of 60 kg reactant/ha. In this version the mass of seeds per plant amounted on the average to 2.25 gm, the mass of seeds per central umbel and top umbel of the first order being equal to 0.93 and 0.66 gm, respectively. Under the background of N90 there was insignificant increase of this characteristics in comparison with the variant of application of N60.