Commercial evaluation of storage solutions for enhanced application of CIPC
Modifications were carried out in commercial box stores with the aim of improving the residue distribution of chlorpropham (CIPC) sprout suppressant to minimise the risk of Maximum Residue Level (MRL) exceedance. The objective of the work was to adopt a range of strategies centred on the use of active recirculation of air/fog. The modifications included simple, low-cost hardware alterations as well as more fundamental changes in air delivery to improve evenness of CIPC application.
Assessments were carried out at commercial store unloading to facilitate sample retrieval and therefore storage duration was variable. Residue distribution was measured using three individual tubers per location, analysed separately, and efficacy assessed using 25 tubers, selected randomly from netted samples placed in boxes at store loading. Stores holding crops across a range of varieties for both the fresh market and processing sectors were assessed.
A simple ‘open suction’ conversion, consisting of an air separator curtain and low-speed recirculation of CIPC fog through open pallet apertures using the store ventilation system, resulted in effective control of residue distribution and good sprout control. Ventilated plenums offer an alternative and performed adequately with slow speed, active recirculation but need to be tailored to take account of individual storage environments and hardware characteristics.