Economics of hot water dipping.

Hot water dipping is an appropriate method to protect apples against spoilage caused by gloeosporium rot. Tests on the varieties Topaz and Ingrid Marie at the OVB Jork (Germany) have demonstrated an effective reduction of spoilage from between 80% and 92% in charges by an infection rate of 40%. The result of an intensive R&D process between 2002 and 2003 is the development of a praxis-tested big box (300 kg) dipping station. With the first Bio Dipping systems now on the market it has now been possible to analyse the economics of this process. The costs of the systems per apple farm have been calculated from the fixed capital costs for the system itself (including maintenance costs) and from the variable costs based on an average crop of 250 t gloeosporium-sensitive varieties, which would be treated with this process every season. The Return on Investment depends largely on the effectiveness of the process in reducing spoilage and on the level of infection within the crop, assuming that losses occur in storage. Based on an average effectivity of 85% and an infection rate of 10% it has been possible to calculate an amortisation within eight years. Higher levels of infection and a consistent effectivity of 85% shorten this time span significantly. The attractions of the hot water dipping process are in the opinion of the research team at the OVB Jork not merely economically convincing in terms of ROI. By reducing the levels of spoilage throughout the entire supply chain, it is for the first time possible to make a significant development in the sustainable quality management of organic apples, providing clear benefits for both consumer, trade and the grower.