Effect of Boron on the Control of Gray Mold and Postharvest Quality of Strawberry (Fragaria × ananassa) Fruit cv. Selva

Strawberry is a highly perishable fruit sensitive to fungal infections especially gray mold caused by Botrytis cinerea, and has a short postharvest life. In this research, the effect of potassium tetraborate on the growth of the above fungus in vitro, as well as on gray mold severity and some qualitative indices of strawberry fruit cv. Selva during cold storage were investigated. In vitro experiment, the concentrations of borate solution were 0 (control), 0.5, 1, 1.5, 2, 2.5 and 3% in two pHs of 7 and 9 added to the Botrytis culture medium, and in in vivo experiments for incubated fruits with the fungus spore suspension, were 1 and 1.5% (pH= 9) and 2 and 2.5% (pH= 7). For the evaluation of qualitative indices, only non-inoculated fruits were treated with different concentration of borate solutions and kept in cold storage. The results showed that Botrytis growth was completely blocked in vitro when borate with the concentrations of 1% or higher (pH= 9) and 2% or higher (pH= 7) was added to the fungus culture medium. Also, treatment of strawberries with 1% borate solution could control gray mold of infected fruits (showing least decay grade) and preserve certain qualitative characteristics including weight loss, tissue firmness and fungal infection during storage.