The Impact of Seeding Dates and Depth on the Productivity of Common Fennel (Foeniculum vulgare Mill.) under the Conditions of the Southern Steppe of Ukraine.

Abstract

In recent years, the popularity of common fennel (Foeniculum vulgare Mill.), a valuable medicinal, spice, aromatic, melliferous, vegetable and ornamental plant, has grown in the world. Fennel belongs to promising highly profitable crops of a wide range of use. It finds application in medicine, cookery, various industries, in veterinary medicine, animal husbandry. InUkraine, fennel is traditionally grown in the western regions where the climate is moderate; its cultivation under arid conditions of the southern Steppe of Ukraine will significantly improve the performance of agricultural enterprises of different types of ownership, especially farms. Our field experiments were carried out in 2015-2017 in the Kherson region on dark chestnut soils typical of the zone. The target of research was the common fennel variety Oksamyt Krymu. The objectives of the present study included determining the effect of seeding dates and depth on the duration of interphase and vegetative periods, biometric characteristics of plants, yielding capacity and seed quality features under arid conditions of the southern Steppe of Ukraine. In the south of Ukraine, fennel seeds are formed during one vegetation period, therefore fennel was grown as an annual crop. In the experiment, the biometric characteristics of plants reached their maximum values in the variant of early spring sowing in the thirdten-day period of March, with a seeding depth of 2-3 cm: plant height was 97.8 cm; leaf surface area made up 27.6 thousand m2/ha; central umbel diameter was 9.4 cm; first order umbels diameter was 7.0 cm. The highest crop productivity and seed quality indices were also recorded under early spring sowing at a depth of 2-3 cm: crop yield was 1.31 t/ha, 1000-seed weight –5.21 g, essential oil content in seeds –5.87% in dry matter, relative yield of essential oil –67.7 kg/ha. Later sowing (in the first or second ten-day periods of April) and any changes in the seeding depth against 2-3 cm led to a decrease in the above-mentioned parameters. Thus, on dark chestnut soils of the southern Steppe of Ukraine, the most favourable conditions for the growth and development of fennel plants, seed formation and the accumulation of essential oils were provided by the interaction of the following parameters of the technological practices investigated: early spring sowing in the third ten-day period of March at the right soil tilth stage and a seeding depth of 2-3 cm.