Enhancement of biocontrol efficacy of Rhodotorula glutinis by salicyclic acid against gray mold spoilage of strawberries

The control activity of Rhodotorula glutinis, salicylic acid (SA), alone or in combination, on gray mold spoilage and natural spoilage of strawberries was investigated. R. glutinis as stand-alone treatment, and the combined treatment of SA at 100 μg/mL with R. glutinis significantly reduced the disease incidence and lesion diameter of gray mold spoilage, respectively at both 20 °C and 4 °C. After 20 d storage at 4 °C, the combination of SA and R. glutinis was more effective than R. glutinis or SA alone treatment. At the concentration of 100 µg/mL, SA had no inhibition on the mycelial growth of Botrytis cinerea in PDA, however, it significantly inhibited spore germination of B. cinerea in PDB. The combination of R. glutinis and SA was the most effective treatment in controlling the natural spoilage of strawberries, and resulted in low average natural spoilage incidence in 6.3% or 6.3%, respectively, compared with 37% or 46.7% in the water-treated control fruit following storage at 20 °C for 3 d or 4 °C for 7 d followed by 20 °C for 2 d.