The Impact of Some Biostimulators on Tuber Yield and Quality of Two Potato Cultivars Planted at Two Densities

Abstract

Nowadays, biostimulants are increasingly being applied to potato crops to increase nutrient efficiency and better tolerate abiotic stress. Aiming to achieve sustainable potato crops, biostimulants have positive effects on crop yield. This research investigates the effects of foliar fertilization, planting density, and environmental conditions on yield and tuber quality (starch, protein, ash, dry matter content) in two potato cultivars, Darilena and Ultra, across two locations (Brașov and Codlea) in the year 2023 and 2024. The experiment involved five foliar fertilizer treatments: control (V1), two biostimulants - Genaktis (V2) and Irys (V3), a third biostimulant - Number One (V4) and a foliar fertilizer with biostimulant properties - Wuxal Macromix (V5). Results showed that Ultra at 53,000 plants/ha combined with biostimulants V4 and V5 achieved the highest yields, particularly in 2023. Darilena consistently recorded higher starch and protein content, especially in 2024 and under lower planting density. PCA and correlation analyses revealed that the yield was negatively associated with starch and dry matter, while starch strongly correlated with dry matter content. These results emphasize the need to align cultivar choice, fertilization strategy, and planting density with local environmental conditions to maximize tuber quality and yield.