S‐carvone effects on Botrytis cinerea and harvested waxflower ( Chamelaucium )

Postharvest ethylene‐mediated floral abscission induced by Botrytis cinerea infection is a major problem for the waxflower ( Chamelaucium ) industry. Socio‐environmentally sound measures for Botrytis control are desirable alternatives to synthetic fungicides. S‐carvone is an essential oil reported to effectively inhibit several fungal pathogens on potato. In the present study, S‐carvone concentrations of 0.64 and 1.27 m M significantly reduced B. cinerea conidial germination in vitro on slides. S‐carvone concentrations of 2.54 and 5.08 mM inhibited B. cinerea germination and suppressed mycelial growth in vitro on agar. However, S‐carvone treatments of 2.54 and 5.08 mM applied to cut waxflower ‘My Sweet Sixteen’ (( C. floriferum × C. uncinatum ) × C. axillare ) sprigs generally gave no positive effects against Botrytis infection and flower abscission, actually promoting both disorders.