Effect of biostimulant application on development of pansy (Viola tricolor var. Hortensis dc.) seedlings

Pansy (Viola tricolor var. hortensis DC.) is a biennial large-flowered hybrid plant cultivated as a popular ornamental plant in urban green areas. The plants prefers sun and well-drained soil, but also tolerate low temperatures. The optimal time for transplanting pansy seedlings in outdoors beds is in autumn, although early autumn frosts can affect the insufficient nutrient uptake, which can be a limiting factor for seedling survival. To avoid these effects, plants can be treated with different growth stimulants such as the biostimulant Radifarm (R). The aim of this study was to investigate the effects of biostimulant Radifarm (R) application on development of pansy seedlings. The experiments were carried out in the glasshouse of the Faculty of Agriculture in Banja Luka, Bosnia and Herzegovina, set up as a split-plot design with treated and untreated plants during 2014 and 2015. In the greenhouse, young plants were treated with biostimulant Radifarm (R) (Valagro SpA, Italy) in concentration of 0.30% while control plants were treated only with tap water. During the experiment, the following parameters were recorded: plant height (cm), plant diameter (cm), number of leaves, and number of flowers. At the end of the experiment root and above-ground fresh, and dry mass were recorded. Biostimulant treatment showed improved results by increasing the examined parameters. Biostimulant application can ensure production of high quality pansy seedlings by overcoming temperature stress and providing good nutrient uptake by the reduction of fertilizers and environmental contamination.