Effect of preharvest spraying Cryptococcus laurentii on postharvest decay and quality of strawberry

• Preharvest spraying with C. laurentii reduced postharvest decay of strawberry fruit.
• The frequency of spraying C. laurentii significantly influenced control efficiency.
• Three applications of C. laurentii before harvest improved biocontrol efficiency.
• Preharvest treatment with C. laurentii did not significantly affect fruit quality.

Application of a suspension (log 8.0/ml) of Cryptococcus laurentii prior to harvest led to a reduction in Botrytis cinerea decay of strawberries stored at 4 or 20 °C, for 12 or 4 days, respectively. The frequency of spraying antagonist significantly influenced disease incidence in strawberry fruit. The best inhibition of disease was achieved when fruit sprayed C. laurentii with three applications that began 6 days prior to harvest, and the incidence of gray mold and natural decay treated with this method was 21% and 11%, compared with 88% and 62% in the control after storage at 20 °C for 4 days. A similar result occurred in the treated fruit after storage at 4 °C for 12 days. Dilation plate counts on Rose Bengal agar and scanning electron microscopy results showed that three applications with C. laurentii at 6, 3 and 0 days before harvest improved its ability to colonize the epidermis of strawberry fruit in the greenhouse and during storage compared to single application. In addition, antagonistic yeast spraying before harvest could reduce the weight loss, delay the decrease of the firmness and ascorbic acid, but had no significant effect on the contents of soluble solids, titratable acidity and fruit surface color. These results suggested that preharvest spraying with C. laurentii might be a promising alternative to fungicide application for decay control of strawberry.

Figure optionsDownload as PowerPoint slide