DPA guidelines for postharvest drenching of apples and pears

April 2007 | Future Orchards® archive resource | DPA post-harvest drenching guidelines

This guideline addresses the use of diphenylamine (DPA) in post-harvest drenching of apples and pears. It is intended as an operational reference for businesses using DPA treatments to manage storage disorders while maintaining disciplined handling, hygiene and treatment practices around the drencher and fruit-handling system.

Post-harvest chemical treatments depend on correct preparation, even exposure and careful management of the treatment solution. The guideline emphasises that growers and packers need to work within registered label directions and maintain equipment and operating procedures that avoid uneven treatment or contamination between fruit lots.

Because drench systems recirculate water and treatment solution, hygiene and solution management are important parts of the process. Record keeping, maintenance, operator care and monitoring of the treatment system support both efficacy and residue-management requirements.

The document should be read alongside current product labels, market requirements and food-safety obligations because registrations and residue limits can change. Its enduring value is the process discipline it brings to post-harvest treatment: correct chemistry, clean equipment, consistent exposure and traceable operating practice.