The effects of some organic applications on fruit quality and biochemical contents in apple (Malus communis L.)

In this study, the effects of treatments that promote plant growth, applied during the full bloom period, on the quality and biochemical contents of the 'Jeromine' apple cultivar were investigated. For this purpose, plant growth-promoting rhizobacteria (PGPR) (3%), Algae extract (15%), and Vermicompost (10 kg tree-1-2%) were applied to the trees. In general, it was determined that the applications increased the quality properties and also had positive effects on the biochemical contents of the fruits, and increased the total antioxidant, phenolic, and flavonoid contents compared to the control treatment. In the study, the highest fruit weight was determined from PGPR + Vermicompost treatment (346.8 g), the highest fruit width was determined from Vermicompost treatment (82.32 mm), the highest fruit length was determined from Vermicompost + Algae treatment (78.23 mm), and the highest fruit flesh firmness (78.99 N) was determined from Algae treatment. It has been determined that Algae application has a significant effect on biochemical contents, and this application has the highest total antioxidant activity (92.29 %inhibition mg 100g-1 ), total phenolic content (121.72 mg GAE 100g-1) and soluble solids content (SSC) (14.10%). The highest flavonoid content was determined in the PGPR+Vermicompost+Algae treatment (38.01 mg catechin 100g-1). The highest acidity (pH) was determined in the Control treatment (3.79), and the highest titratable acidity was determined in the PGPR+Vermicompost+Algae treatment (0.40%). The highest fruit color values determined from treatments which Control (L* value 48.38), Algae (a* value 24.76), PGPR+Algae (b* and c* value 19.27-30.36, respectively), and PGPR+Vermicompost+Algae (h° value 45.80).