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Novel approaches to prevent and control postharvest diseases of fruits M Mari,* F Neri and P Bertolini CRIOF – Università di Bologna, Via Gandolfi, Cadriano, Bologna, Italy Abstract Purpose of review: Alternative methods to fungicide treatments have been studied in order to prevent fruit losses in the postharvest phase. Within these methods the applications of antagonist microorganisms, plant bioactive compounds and elicitors of resistance showed interesting results. This article reviews recent advances in postharvest disease control, paying attention to limits and possible enhancement of each method. Recent findings: Recent studies have reported that: (1) despite the substantial progress obtained with biological control agents (BCAs), these are still not routinely applied in the postharvest phase. The main drawbacks can be summarised as follows: insufficient and inconsistent performance of BCAs; difficulty in obtaining an adequate formulation; and difficulty in controlling rot caused by latent infections. (2) The use of plant bioactive compounds has shown that the treatment conditions (concentration, form of application, formulation, exposure time, time of treatment, etc) should be established not only in relation to active substance and fungal pathogen, but also to fruit and vegetable response to treatment. The different responses found in many studies between cultivars indicate cultivar specificity in the product-pathogen-volatile interaction. A barrier to the use of plant bioactive compounds may not be efficacy, but rather the off-odours caused in fruits and vegetables or the phytotoxicity. (3) Elicitors showed fungicidal activity that is sometimes inconsistent with fungistatic effects only and related to treatment timing and the developmental stage of the plant. Heat treatments by hot water (HW) dips, hot dry air, vapour heat or very short water rinse and brushing appear more promising. Direction for future research: To overcome the drawbacks that have arisen with the use of BCAs, the integration of the antagonist with other methods such as generally recognised as safe substances, heat, etc has been proposed; this strategy could produce an additive or synergic effect on disease control. The antifungal activity of plant volatiles could be improved under vacuum conditions. The combination of plant active compounds with high hydrostatic pressure in dipping treatments has been suggested. In the future, heat treatments will be fundamental for organically grown crops that, untreated with chemical fungicides, suffer due to a relatively high rate of decay in the postharvest period. Keywords: biological control agent; plant volatile compounds; elicitors; heat treatments Stewart Postharvest Review 2007, 6:4 Published online 01 December 2007 doi: 10.2212/spr.2007.6.4 |