CONTAMINATION OF LAVANDIN PLANTATIONS UNDER DIFFERENT IRRIGATION METHODS AND FERTILIZATION SYSTEMS

Abstract

Goal. Lavandin (Lavandula hybrida Rev.) is a promising perennial essential oil crop for the conditions of southern Ukraine – an interspecies hybrid of narrow-leaved lavender (Lavandula angustifolia Mill.) and broad-leaved lavender (Lavandula latifolia Medic.), created by artificial crossing. A significant factor that can limit the productivity of this plant is weediness of plantations, especially in the first to third years of use. Weeds are competitors of the culture for moisture, light and nutrients, reservoirs of pathogens, additional food base for pests, which affects the yield of flower raw materials, the service life of lavender plantations, and therefore the profitability of its cultivation. The primary stage in decision-making regarding the control of unwanted vegetation is the systematic monitoring of the species composition of weeds. The purpose of the presented study was to determine the influence of irrigation methods and fertilization systems on the weediness of Lavandula hybrida Rev. plantations. in the conditions of southern Ukraine. Methods. The experiment was conducted during 2021–2023 on dark chestnut slightly saline, medium loamy soils of the Krynytsia PE, located in the village of Ingulets, Kherson district, Kherson region. The scheme of the experiment included drip surface, drip underground, sprinkler methods of irrigation and two mineral and organic fertilization systems. Results. The species composition of weeds in the period of spring growth of lavender plants in the first year of use, on average for 2021–2023 of the study, was represented by short-year and perennial types of segetal vegetation, among which spring-late (33%), winterwinter (22%) and rhizomes were predominant (22%). The share of rhizome weeds in lavender plantations was 11%, early spring weeds and winter weeds – 6%, respectively. Conclusions. The initial weediness of lavender plantations in the first to third years of use during the spring growth of plants was high and significantly depended on irrigation methods and plantation fertilization systems. Irrigation led to an increase in the number of weeds, especially when sprinkler irrigation was used. The maximum weediness in the years of the study was determined in the option of applying the organic fertilization system, which involved the application of manure before planting plantations. The number of weeds under this system varied between 318.3–432.5 pcs./m2 in the first and 110.9–188.2 pcs./m2 in the third year of use, depending on the irrigation methods.