Study on the impact of universal and organic fertilizers on development and flowering of Petunia and Pelargonium cultivars

Nadejda Zapryanovа, Denichka Manolova

Abstract: Ornamental pot flower crops grow on limited amount of soil, which leads to a rapid depletion of nutrients. Balanced supply with macro- and micro nutrients plays significant role in the growth and flowering. For maintaining a lasting decorative effect, various organic and mineral fertilizers are used. The present research was conducted at the Institute of Ornamental and Medicinal Plants - Sofia. Pot experiments were carried out in greenhouse conditions to study the influence of several fertilizers: Grandiol, Masterbland, Lactofol, Compovet, Cocovet and Bio Start 93 on the growth and development of petunia (Petunia x hybrida), cv. „Surfinia – Red‟ and pelargonium (Pelargonium zonale), cv. „Sumer idols – true red‟. The mineral fertilizer Masterblend that is commonly used in horticulture showed better effect on the development, formation and flowering of pelargonium.The plant height exceeded the control with 120% and the plant diameter was 130% over the nonfeeded plants. The slow-releasing fertilizer Grandiol had positive influence on the size of pelargonium inflorescence. The use of biofertilizer stimulated the formation of larger inflorescences in pelargonium. At the applied doses no symptoms of phytotoxicity were noticed. In petunia, the use of organic fertilizers had lower impact on vegetative development, with the exception of Kokovet. From universal fertilizers, Lactofol showed stimulating effect on its growth.

Keywords: development; flowering; organic and mineral fertilizers; Pelargonium zonale; Petunia

Date published: 2019-10-30