Fertilizer Containing 5-Aminolevulinic Acid Affects Sour Cherry Fruit Quality and Biological Characteristics

The physiological role of 5-aminolevulinic acid (5-ALA) in plants, and three seasons of 5-ALA-based foliar fertilization of sour cherry (Prunus cerasus L.) were examined with respect to fruit quality and leaf characteristics. The research was carried out at the Poznan University of Life Sciences Research Station in western Poland on sour cherry 'English Morello' trees grafted on Prunus mahaleb rootstock from their 6th to 8th growth year. Two concentrations of fertilizer foliar applications were evaluated with respect to their effect on leaf color, relative chlorophyll content, leaf area, and leaf mineral composition, as well as yield and fruit quality parameters including: mean fruit weight, fruit firmness, total soluble solids and fruit color at harvest. Significantly positive effects of the evaluated treatments on fruit soluble solids, mean fruit weight, fruit color, yield and efficiency index were found. Relationships between applied fertilization and leaf quality characteristics depended primarily on the experimental season.