Natural volatile compounds control Botrytis on strawberry fruit

The biological activity of a diverse group of natural volatile products including lipoxygenase-lyase metabolites and related compounds were studied for their ability to inhibit Botrytis cinerea Pers. mold on strawberry fruit. Many of these compounds are common components of fruit and vegetable aromas and of the human diet, and have been implicated in plant pest-defense mechanisms. In a simple bioassay system, individual strawberry fruit, naturally-inoculated with Botrytis, were exposed to the volatile compounds at a range of vapor phase concentrations. Several compounds, including benzaldehyde, methyl benzoate, methyl salicylate, 2-nonanone, 2-hexenal diethyl acetal, hexanol, and E-2-hexen-1-ol, inhibited Botrytis development in the ppm range. Adverse effects on fruit quality were noted with some compounds. A continuous exposure of fruit to volatiles may be required for some of the compounds to have an inhibitory effect, while others may be effective with exposures of short duration. Headspace analysis of the storage atmosphere showed that some of the compounds were converted to volatile metabolites of potential significance to microbial spoilage or fruit quality. Some of the volatile compounds show promise as postharvest fumigants for control of Botrytis on strawberry fruit.