Effect of hydroethanolic extracts of Eucalyptus globulus and Allium fistulosum on strains of Botrytis cinerea in inoculated strawberries

The strawberry (Fragaria x ananassa) faces sustainable production challenges due to its high susceptibility to pathogens like Botrytis cinerea. This research aimed to evaluate the inhibitory potential of eucalypt (Eucalyptus globulus) and Welsh onion (Allium fistulosum) extracts under in vitro and in vivo conditions in controlling B. cinerea. The in vitro mycelial inhibition of the extracts was evaluated by the diameter and the mycelial growth rate of the fungus for 5 d, with the application of low (5.6 μl ml-1), medium (11.1 μl ml-1), and high (16.7 μl ml-1) concentrations of extracts. The antifungal activity of the extracts on the fruits was determined by quantifying the incidence and rate of decay in inoculated strawberries after 5 d of storage. The in vitro evaluation showed that the high concentration of the A. fistulosum extract was more efficient in controlling the mycelial growth of B. cinerea, showing averages of 31.66% inhibition, 68.33% mycelial growth rate, and 11.92 mm d-1 mycelial growth velocity, different (P≤0.05) in comparison to the other concentrations. The in vivo tests showed that the E. globulus extract had the lowest incidence on the fruits, with 81.11%, reduced fruit decomposition by 19% compared to the positive control, and evidenced the highest number of fruits without visible changes during the five evaluation days. The analysis of the extracts demonstrated a significant effect on the control of B. cinerea, as well as on the shelf life of the fruits.