Fumigation of fresh herbs with phosphine as a new quarantine treatment.
Simcha Finkelman*, Shlomo Navarro, Hagit Navarro, Gilad Ashbell, Uzi Glaser Food Technology International Consultancy Ltd., Israel
* Corresponding author e-mail: finkelman@ftic.info
Abstract: Introduction of new pests into new habitats is the main concern of all agricultural quarantine authorities. To prevent these dangers all countries enforce quarantine regulations on agricultural products demanding that the product will be free of live insect pests. To provide high quality products the fresh spices growers must market the harvested herbs within 3 days kept at temperature of about 4°C. Today exported herbs are fumigated with methyl bromide (MB) to achieve a total mortality of all insect developmental stages found in the products, MB is highly phytotoxic and only effective as a pesticide when the fumigation is carried out at temperatures over 21°C. To develop fumigation technology that will be suitable and effective to replace MB, experiments were carried out using phosphine. Experiments were carried out under laboratory conditions at temperature of 4°C and for 24h exposure time. The tested herbs were: dill, parsley, tarragon, basil, mint, sage, oregano, thyme and rosemary. The insect pests: Laphigma spp., Prodenia spp., Geometridae, thrips and Bemisia tabaci were collected at their adult and larval stage with the herbs from the field and they were exposed to the phosphine fumigation treatment. The effective concentration of the gas that was found suitable to attain complete mortality of all groups of tested insects was 700ppm. It was also found that the treatment killed all developmental stages of mites Tetranychus urticae. Most herbs had no quality deterioration due to the treatment even after 14d of storage, except basil and mint which were found sensitive to the treatment. These results indicated that phosphine fumigation can be an effective quarantine treatment that can control field insect pests after exposure of 24 hours at the low temperature of 4°C and can be considered as MB alternative treatment.
Key words: fresh herbs, phosphine fumigation, quality preservation, quarantine treatment, low temperature, insect control, methyl bromide alternative.
