RUGALA PRODUCTIVITY UNDER DIFFERENT OPTIONS OF CULTIVATION IN CLOSED GROUND CULTIVATION STRUCTURES

Abstract

The growing role of controlled environment technologies and the need to optimize the light regime as a key factor in regulating the photosynthetic productivity of leafy vegetable crops determine the current scientific and practical significance of research in this area. Arugula (Eruca sativa L.) is characterized by high plasticity to the spectral composition of light, which makes it a promising object for improving LED supplementary lighting regimes in order to increase yield and preserve product quality in closed soil conditions. The research was conducted in 2023–2024 in the greenhouse of the Green Farm private enterprise using hydroponic cultivation technology with full control of microclimate and nutrition parameters. The objects were five varieties of arugula: Gracia, Tricia, Agris, Lybid, Sicilia. The effect of three variants of LED lighting (460–620–660 nm) with a constant proportion of blue light (25%) and different ratios of red parts of the spectrum was studied. Plants grown under natural light served as controls. Biometric indicators, leaf surface area, and accumulation of fresh and dry biomass to the technical maturity phase (tillering) were evaluated. It was found that the most effective for most varieties is the spectral ratio 460–620–660 nm (%) 25–25–50, which provided maximum growth and yield. The 25–0–75 variant was the least effective and caused a significant decrease in biomass in all varieties. An increase in the proportion of short–wave red radiation stimulated faster formation of the leaf apparatus at the early stages of development (especially in the Lybid variety). In the varieties Gratsia and Siciliya, temporary inhibition of germination was observed, however, by the tillering phase, their assimilation surface exceeded the control by 40–90%. Long–wave red light had the most pronounced inhibitory effect: plants did not reach the tillering phase, and biomass accumulation occurred five times slower than in the control. The mixed red spectrum contributed to an increase in yield (especially in the varieties Gracia and Agris), but was accompanied by a decrease in the content of photosynthetic pigments and secondary metabolites. The results obtained confirm the need to optimize the spectral composition of supplementary lighting, taking into account the varietal characteristics of arugula and the balance between quantitative and qualitative indicators of production.