Preharvest exposure to UV-C radiation: impact on strawberry fruit quality.

Extending strawberry production season through cultivation in high tunnels or greenhouses offers access opportunities to niche markets. In these confined environments maintaining adequate phytosanitary protection may be very challenging under organic production, since effective chemical pesticides cannot be used. Physical treatments might represent interesting alternatives worthy of consideration to control pests in organically-grown crops. Among these physical treatments, UV-C hormesis has been reported to activate innate plant defenses and to slow down ripening and senescence in postharvest systems. There is however a lack of information on its possible effects on growing plants and how such treatment might impact fruit quality. In the present study, ‘Charlotte’ strawberry plants were exposed to UV-C light (60 mJ/cm2) during growth according to a repeated schedule from flowering until fruit reached commercial maturity. Mature fruits were harvested and quality parameters (firmness, color, anthocyanins and ellagic acid) were assessed. Higher firmness and ellagic acid content are discussed in line with the possible influence of UV-C in delaying ripening and senescence as observed in other fruits treated at the postharvest stage.