Management of postharvest decay in South African Forelle pears

Abstract: Postharvest losses due to decay can be significant in South African Forelle pearsdestined for export markets. In order to develop a decay management strategy, bloom andpostharvest fungicide applications were evaluated for their efficacy in reducing decay in fruitfrom three commercial Forelle orchards. Iprodione and benomyl were applied at full bloom and75% petal drop, and procymidone at full bloom. Iprodione, pyrimethanil + imazalil, pyrimethaniland the biological control agent Cryptococcus albidus were applied as postharvest dip treatments.Control fruit were treated with water. Fruit were stored at -0.5°C regular atmosphere for 14weeks, ripened at 21°C for 7 days and then evaluated for decay. In the control treatment, calyxend decay (CED) incidence was significantly higher in orchard three only. Iprodione, benomyland procymidone, applied at bloom significantly reduced CED in this orchard, while benomylsignificantly reduced CED in orchard one. None of the postharvest treatments significantlyreduced CED caused by Botrytis cinerea. Iprodione significantly reduced decay caused byAlternaria in orchard one when compared to the control. The postharvest treatments reduceddecay caused by other minor pathogens when compared to the control fruit in this orchard. Decayfrom orchards two and three was not significantly reduced by any of the postharvest treatments.Cryptococcus albidus did not significantly reduce decay in Forelle pears for all orchards.