Effect of alternative application methods of Iprodione for post-harvest control of Botrytis decay on pears

• In 2010 Packhams Triumph and Forelle pears were dipped and treated with a standard and electrostatic system (ESS) atomizer.
• Iprodione at 1ml/L was used in the dip treatment and 11ml/L Iprodione was used for the two atomizer treatments.
• The quantitative spray coverage was generally lower on Packhams Triumph than on Forelle
• With Packhams Triumph, the quantity of spray cover was similar for the dip and ESS atomized fruit and it was significantly higher with the standard atomizer. However in Forelle pears the quantity of the spray cover in the dip was higher compared to both atomizers.
• Residues were lower in the dip treatments compared to the atomizers. Residues in atomized fruit were similar for the ESS and standard atomizers with the exception of Forelle pears in which case residues with the standard atomizer was higher.
• In Packhams Triumph, Botrytis decay was reduced by all the Iprodione treatments. However, despite the differences in quantity of spray cover between application methods, as well as residues, decay control did not differ significantly.
• A similar pattern emerged for Forelle pears, in terms of decay control, with no significant differences occurring between Iprodione treatments. However, fruit treated by means of a dip tended to develop less Botrytis decay compared to the atomizer treatments.
• Due to the fact that decay control was not improved with the ESS atomiser, a high volume spray (HVS) was tested in 2011.
• The quantitative spray deposit was generally higher on the Forelle pears compared to the Packhams Triumph pears. It was also higher for the dip compared to the atomiser treatments, which was similar. .
• Residues were generally lower in the dip than with the HVS which was in turn lower than the standard atomiser.
• Despite the lower residues, decay control was generally improved with the dip treatment followed by the HVS.

The HVS generally showed an improvement in decay control compared to the standard atomiser, but it was only significant in the case of the Forelle pears