Encapsulated citrus peel essential oil in pegylated mesoporous silica nanoparticles for postharvest control of Botrytis cinerea in strawberry.

Nanotechnology-based pesticide delivery systems provide controlled release of agrochemicals along with enhanced stability, target specificity, and reduced environmental impact. Strawberries (Fragaria × ananassa), valued for their flavor, nutritional content, and antioxidant properties, face a short shelf-life and significant postharvest losses due to Botrytis cinerea (B. cinerea)-induced decay, posing a challenge to producers. This study reports the development of a biocompatible, botanical nano-formulated fungicide (BNF) to manage B. cinerea, as a resistant post-harvest pathogen. BNF, encapsulating citrus peel essential oil (CEO) within a biocompatible inorganic-organic matrix consisting of silica nanoporous and polyethylene glycol (PEG), was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Thermogravimetric Analysis (TGA), Gas chromatography-mass spectrometry (GC-MS) analysis, and Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. To evaluate the efficacy of our treatments against B. cinerea, Signum (BASF), a commercial fungicide, was used as a positive control. Its antifungal efficacy was assessed at four different concentrations (0, 5000, 7000, and 10000 mg L-1, when BNF contains 10% of the active ingredient) and Signum (1000 mg L-1) against B. cinerea on strawberry flowers and postharvest fruits. Results indicate that BNF at 5000, 7000, and 10,000 mg L⁻¹ significantly inhibited the growth of B. cinerea (p ≤ 0.01) and reduced fruit spoilage. Notably, BNF at a concentration of 10,000 mg L⁻¹ achieved 74.03% inhibition, closely comparable to Signum (77.52% inhibition), while the water-treated control (BNF0) showed only minimal inhibition (13.01%). These findings demonstrate BNF's potential as an effective and sustainable alternative to conventional fungicides for managing B. cinerea in strawberry production, with a recommended dose of 10,000 mg L⁻¹ for optimal efficacy. This study demonstrates that BNF is a promising eco-friendly alternative to synthetic fungicides for controlling B. cinerea, enhancing strawberry shelf life, and reducing chemical residues, with potential utilization in other crops.