Dates fumigation with phosphine

Stored dates are usually infested by sap beetles and moths. For years, the common practice for dates disinfestation was fumigation with methyl bromide (MB). After MB phase-out, heat treatment and modified atmosphere are used. However, there are several limitations of these methods. In search for alternatives for dates disinfestation, fumigation by phosphine was evaluated. Commercial fumigations of Medjool dates variety using phosphine were conducted in a standard 20 ft. shipping container. Two formulations of phosphine were used: Magtoxin® Plates 56% (Detia Freyberg GmbH, Germany), and Phostoxin® Tablets 56% (Detia Freyberg GmbH, Germany). The phosphine dosage range was 1-4 g/m3. The exposure time range was 24-72 hrs. Several fumigations were carried out by an innovative phosphine generator model OMT 501 developed by Universal Probes. Most fumigations carried out demonstrated total dates disinfestation. The application of Magtoxin plates, especially using the OMT 501 demonstrates significant advantages versus Phostoxin tablets; the advantages were in quicker gas development, and achieving much higher maximum and pre-ventilation phosphine concentration levels. Upon fumigation using the OMT 501, plates are easily collected and disposed, no residual dust left on the dates, which avoided their contamination. No phosphine residues were found in the fumigated dates, neither changes in organoleptic properties were noted. Phosphine fumigation using the phosphine generator model OMT 501 provides safer, quicker, more efficient dates disinfestation.