The Impact of Biopreparations and Sowing Dates on the Productivity of Fennel (Foeniculum vulgare Mill.)

is a valuable medicinal and aromatic plant. The introduction of such an ecofriendly element as presowing seeds inoculation with phosphate mobilizing microbial biopreparation into the growing technology is especially important in the cultivation of this crop. It is connected with an extensive use of fennel in the production of medicines, including the remedies for children. Under the moisture deficiency conditions of the southern Steppe of Ukraine, the study on the effectiveness of phosphate mobilizing biopreparations depending on the impact of sowing dates is particularly relevant. Our field experiments were carried out in 2017-2019 in the Kherson region on the dark chestnut soils typical for the southern Steppe of Ukraine. Presowing seeds inoculation with biopreparations of phosphate mobilizing bacteria Albobakteryn and Polimiksobakteryn positively affected the indicators of fennel productivity and yield quality. Among the microbial preparations studied, a preference for Polimiksobakteryn was recorded. The research findings indicate a tendency to lower the quantitative and qualitative indicators of fennel seed yield from early to late sowing. The most favourable conditions for the productive processes of fennel plants and accumulation of essential oil were ensured by the interaction of seeds bacterization with the Polimiksobakteryn biopreparation and early spring sowing at the right soil tilth stage in the third ten-day period of March. In this variant, the yielding capacity was 1.41 t/ha, the weight of 1000 seeds reached 5.61 g, the essential oil content in the seeds amounted to 6.13% in dry matter, the relative yield of essential oil being 76.1 kg/ha. The introduction of microbial preparations of phosphate mobilizing bacteria into the technology of fennel cultivation is a promising environmentally friendly approach to improving the crop productivity.