V-HF or "Vacuum Hermetic Fumigation"

The use of low pressures to control insects in post-harvest storage has been studied in the past. It was shown that mortality is caused mainly by the low partial pressure of oxygen that results in hypoxia and also dehydration due to removal of water vapor under vacuum.

Until recently, the possibility of using low pressures at the large scale commercial level to control insect infestations had been abandoned due to the requirements for massive, rigid and expensive structures needed to withstand the low-pressures.

Recently however a new and innovative technology was introduced by members of our team for the hermetic storage of durable commodities, and is now in use on an industrial scale. The structures consist of flexible plastic chambers with manufacture specifications to a level of gas tightness that also enables treatments with modified atmospheres or fumigants without significant gas loss over short exposure times. These structures are termed "GrainPro Cocoons".

It has now been shown that these "cocoons" can be adapted take the place of such rigid vacuum chambers. To achieve the low pressures in the flexible liners, sufficiently low pressures (25-50 mmHg absolute pressure) can be obtained using a commercial vacuum pump and maintained for indefinite periods of time.

Work on this innovative technology is ongoing but further information may be obtained through the following publications:

• Finkelman, S., Navarro, S., Rindner, M., Dias, D., Azrieli, A., 2004. Effect of low pressures on the survival of three cocoa pests at 30°C. Journal of Stored Products Research 40:499-506.
• Isikber, A. A., Navarro, S., Finkelman, S., Rindner, M., Azrieli, A., and Dias, R. (2004) Toxicity of propylene oxide at low pressure against life stages of four species of stored product insects. J. Econ. Entomol. 97 (2):281-285
• Isikber, A. A., Navarro, S., Finkelman, S., Rindner, M., and Dias, R. (2004) Influence of temperature on toxicity of propylene oxide at low pressure against Tribolium castaneum. Phytoparasitica 32(5):451-458.
  
• Navarro, S., Isikber, A.A., Finkelman, S., Rindner, M., Azrieli, A. and Dias R. (2004) Effectiveness of short exposures of propylene oxide alone and in combination with low pressure or carbon dioxide against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) . J. stored Prod. Res. 40: 197-205.
• Finkelman, S., Navarro, S., Rindner, M., Dias, D., Azrieli, A., 2003. Effect of low pressures on the survival of cacao beans insects stored at 18°C. Journal of Stored Products Research 39, 423-431
• Finkelman, S., Navarro, S., Isikber, A., Dias, R., Azrieli, A., Rindner, M., Lotan, Y. Debruin, T., 2003. Insects control of cocoa pests using a novel vacuum approach. In: Credland, P. F., Armitage, D. M., Bell, C. H., Cogan, P. M., Highley, E., [Eds] Proceedings of the 8th International Working Conference on Stored Product Protection, July 22-26, 2002, York, UK, pp 579-582.
• Navarro, S., Finkelman, S., Rindner Miriam, Dias, R. and Azrieli, A. (2003) Field trials on biogenerated V-HF systems to control the large narcissus fly. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions (eds. G.L. Obenauf and R. Obenauf) Hotel Double Tree, San Diego, California, November 2-6 2003. 73-1;2. San Diego, CA, USA.
• Finkelman, S., Navarro, S., Isikber, A., Dias, D., Azrieli, A., Rindner, M., Lotan, Y., Debruin, T., 2002. Application of vacuum to sealed flexible containers: a viable alternative to disinfestation of durable commodities with methyl bromide. In: Batchelor, T. A., and Bolivar, J. M., [Eds.] Proceedings of International Conference on Alternatives to Methyl Bromide. March 5-8, 2002, Sevilla, Spain, 145-149.
• Navarro S., Finkelman S., Donahaye E., Dias R., Miriam Rindner and Azrieli A. (2001) Integrated storage pest control methods using vacuum or CO₂ in transportable systems. Meeting of the IOBC WPRS / OILB SROP working group integrated protection of stored products (eds. A. Cornel and S. Navarro), p. 31 Lisbon, Portugal.
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• Navarro S., Finkelman S., Donahaye E., Miriam Rindner, Dias R., Azrieli A. (2001) Laboratory and field tests on vacuum or CO₂ for the control of storage insects. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions (eds. G.L. Obenauf and R. Obenauf), p. 68-1. San Diego, CA, USA.
  
• Navarro, S., and Calderon, M., 1979. Mode of action of low atmospheric pressures on E. cautella (Wlk.) pupae. Experientia 35, 620-621.
• Navarro, S., Donahaye, J. E., Dias, R., Azrieli, A., Rindner, M., Phillips, T., Noyes, R., Villers, P., DeBruin, T., Truby, R., Rodriguez, R., 2001. Application of vacuum in a transportable system for insect control. In: Donahaye, J. E., Navarro, S., Leesch, J., [Eds.] Proceedings of an International Conference on Controlled Atmosphere and Fumigation in Stored Products, Fresno, CA, 2000. Executive Printing Services, Clovis, CA, 307-315.
• Navarro, S., 1978. The effects of low oxygen tensions on three stored-product insect pests. Phytoparasitica 6, 51-58.