A Synergistic Approach to Post‐Harvest Strawberry Disease Management: The Combined Effect of Crocin in Saffron Stigma Extract and Mountain Rue Essential Oil for Enhanced Fungal Infection Control

Fungal contamination poses a significant threat to the quality and shelf life of fresh produce, particularly during post-harvest storage and transport, resulting in substantial economic losses. Although synthetic fungicides remain the primary means of fungal control, their environmental persistence and potential health risks underscore the urgent need for safer natural alternatives. In this study, the chemical composition of Ruta montana essential oil (EO) was determined using gas chromatography–mass spectrometry (GC–MS). Its antifungal activity against the major post-harvest fungal pathogens of strawberries (Geotrichum candidum, Rhizopus stolonifer and Botrytis cinerea) was assessed using broth macro-dilution and poisoned medium assays. The synergistic potential of R. montana EO in combination with an aqueous saffron (Crocus sativus L.) extract enriched in crocins was further evaluated via the agar well diffusion method and confirmed through in vivo application on strawberries. The dominant compounds of the R. montana EO were 10-Nonadecanone (51.55%), Psoralen, (12.2%), and 2-Nonanone (4.66%). Strong antifungal activity was observed, with the EO-crocin extract mixture exhibiting enhanced efficacy and pronounced synergistic interactions. These results highlight the potential of R. montana essential oil, particularly when combined with saffron-derived crocins, as an eco-friendly and effective alternative to synthetic fungicides for managing post-harvest fungal infections in the food industry.