Effect of a microorganism-based biostimulant on sweet orange plant behavior, fruit quality, and postharvest shelf-life

Sweet orange fruits suffer losses during growth and after harvest due to rot and physiological disorders, with significant economic implications.
Novel sustainable approaches based on microorganism formulations are being used to promote plant growth, stress resistance and fruit quality.
This study aimed to assess the effect of field application of Methylobacterium symbioticum-based biostimulant (WO2020/ 245675A1) on plant behavior, oranges quality preservation, and stress defense increase throughout cold storage and shelf-life.
The trial was assessed at CREA’s experimental farm, on ‘Tarocco Sciara’ grafted on ‘Carrizo’ citrange.
Biostimulant was sprayed on the trees’ canopy in spring and autumn at two dosages (500 and 1000 g ha^‑1). Water treatment was used as control.
Plants were evaluated by measurement of the chlorophyll, yield, and qualitative traits.
Soon after harvest, oranges were stored at 5±1°C and 85-90% relative humidity.
Fruit quality was assessed at harvest and throughout cold storage and shelf-life by analyzing epiphytic microbial load and pomological and chemical-physical parameters.
Weight loss, decay incidence, and physiological disorders were also evaluated during storage.
Promising results were obtained for color, texture, and ripening ratio values.
No significant differences were found among yields although a higher weight (249.3 g) was observed in treated fruit, compared to the control (206.4 g). A general quality improvement and shelf-life extension of treated fruits was obtained, thereby extending the marketing period.

XV International Citrus Congress

F. Ferlito, M.C. Strano, M. Caruso, E. Nicolosi, S. Trovato, S. Alessandro, M.E. Porto, E. Napoli, B. Torrisi, M. Allegra, G. Las Casas

citrus, ‘Tarocco Sciara’, Methylobacterium symbioticum SB23 (WO2020/ 245675A1), plant physiology, antioxidant activity

https://doi.org/10.17660/ActaHortic.2026.1448.50