Occurrence of gray mold in stored strawberries as affected by ripeness, temperature, and atmosphere

Development of postharvest decay in strawberries in general and gray mold caused by Botrytis cinerea in particular, was evaluated, specifically: (1) the effect of controlled atmosphere (CA; 5% O2 + 15% CO2) on different developmental stages of the pathogen; (2) the interaction of fruit ripeness and CA storage among fruit stored for 1 or 2 weeks at normal cold storage temperatures (4 or 10°C) for commercial handling; and (3) the residual effects of CA storage after transfer to air on strawberry susceptibility to fruit rot. Delaying CA establishment for 12 or 24 h at 20°C after wound inoculation resulted in progressively more disease development, suggesting that the CA had a greater inhibitory effect on B. cinerea spore germination vs. mycelial growth. The least decay occurred on three-quarter colored fruit stored in CA vs. air and at the lower temperature, and CA had a greater effect at 10°C than at 4°C. These effects persisted during a 24-h display treatment (fruit held in air at 20°C after the main storage treatments). Additionally, inoculation following 1 or 2 weeks storage at 4 or 10°C indicated that CA helped strawberry fruit maintain resistance to gray mold, especially at the higher storage temperature.