Evaluation of plungers for accurate determination of harvest maturity of Imperial, Soldonnè, Bebeco and Charisma apricots

The objective of the trial was to survey and report on the flesh firmness of commercially harvested Imperial, Bebeco and Soldonnè apricots, using a penetrometer fitted with a 6 mm plunger. During 2008, harvest maturity parameter readings were evaluated relative to fruit quality after storage. Imperial, Bebeco and Soldonnè apricots from different producers, and packed for export, were sampled from commercial packhouses. Sampling was conducted periodically from early in the harvest window of each cultivar to late in the window. Results recorded after storage highlighted the risk of storing Imperial apricots when harvested softer than 2.0 kg, and Bebeco apricots harvested softer than

2.5 kg, as this fruit developed high levels of internal disorders. This trend was similar to that reported for Supergold in 2007. Advanced skin colour did not in all cases indicate over maturity and did not always result in poor quality after storage. This trend could not be established in Soldonnè apricots. In 2009 the trial was repeated with Imperial apricots. Due to unavailability of Bebeco and Soldonnè apricots packed for export, Charisma apricots were included in the trial. For Imperial apricots the results obtained in 2008 were confirmed. There was a better correlation between flesh firmness at harvest and internal quality than skin colour at harvest and internal quality. This was relevant after cold storage as well as after shelf life. The results indicated that a minimum flesh firmness of 2.2 kg would ensure internal disorders < 1% after cold storage and < 10% after a shelf life period of 5 days at 10°C. Flesh firmness at harvest can therefore be used to predict internal quality after cold storage followed by shelf life on Imperial apricots. Skin colour and flesh firmness of Imperial and Charisma apricots harvested within the skin colour and flesh firmness ranges as in this trial, can not be used to predict shrivel.