2.4. Efficacy of H.uvarum combined with different concentrations of SA (or SBC) on control of gray mold in grape fruit
Grapes berries were divided into 5 groups. Three groups of berries were immersed in SA solutions with concentration of 1, 2 and 4mmolL−1 for 2min, respectively. The fourth group was not treated.The last group that was immersed insterile distilled water
was used as the control. After air-drying, the treated fruit were stored at 25◦C, RH 90–95% condition for 1 day. A uniform wound of 4mm deep and 3mm wide was made at the equator of each fruit using the tip of sterile dissecting needle. Aliquots (10L) of 1×108 CFUmL−1 yeast suspensions were pipetted into the wound site, except for the control group which was treated with sterile water. After 2h, 10L of the 1×105 sporesmL−1 suspension of B. cinerea was inoculated into each wound. All these fruit were airdried again and then stored at 25◦C, RH 90–95% for 3 days. The lesion diameters and disease in cidence were determined after incubation. Thirty fruit constituted a single replicate. The experiment was repeated twice with three replicates per treatment. The effect of H.uvarum combined with different concentrations of SBC on grape lesion diameter and disease incidence of B. cinerea infection was studied using the similar procedure as for SA.The SBC solutions of 1, 2 and 4% concentrations were used.