Comparative Analysis of Growth Regulators and Fertilizers Effects on Morphometric Parameters of Ornamental Annual Flower Crops in Urban Container Cultivation

Relevance. Modern megacities increasingly utilize container floral landscaping as a versatile tool for urban landscape design. However, under container cultivation, flowering plants are exposed to heightened stress factors that diminish their aesthetic qualities and shorten the effective lifespan of compositions. Consequently, the development of adaptive agrotechnical methods to fully realize the decorative potential of plants in urban environments is of paramount importance. Objective. This study evaluates the efficacy of growth regulators and fertilizers in enhancing the ornamental traits of two popular annual species – French marigold ( Tagetes patula L.) and wax begonia ( Begonia semperflorens-cultorum Hort.) – under street pot conditions. Methods. The study subjects were annual flowering plants: French marigold cv. Petit Harmony and wax begonia cv. Senator Red F 1 . Investigated factors included growth regulators (Buton, Domotsvet, Zircon, Epin-Extra), fertilizers (Siliplant, Tsitovit, EcoFus), and their combinations. Regular foliar treatments with the aforementioned preparations were applied from seedling transplantation into containers. At peak flowering, two key morphometric ornamental parameters were assessed: the number of flowers (inflorescences) per plant and flower (inflorescence) diameter. Results. Regular foliar treatments of seedlings post-transplantation with growth regulators (Buton 0,1%, Domotsvet 0,02%, Zircon 0,01%, Epin-Extra 0,02%) and fertilizers (Siliplant 0,3%, Tsitovit, EcoFus 0,5%), as well as tank mixtures of Zircon with EcoFus and Siliplant, significantly improved ornamental metrics-flower count and diameter. For French marigold, the highest efficacy was observed with Zircon+EcoFus (286% increase in inflorescences) and Domotsvet (26,9% larger flower diameter vs. control). Wax begonia responded best to Siliplant, with a stable 50% increase in flower count across weather conditions, while Zircon maximized flower size (43,5% vs. control). Notably, Siliplant demonstrated high adaptogenic activity for both species under stress. These findings support the use of these preparations to enhance ornamental value in urban greening.