EFFECT OF HYDROSTATIC PRESSURE ON THE VIABILITY OF EPN NATIVE ITALIAN STRAINS STEINERNEMA FELTIAEAND HETERORHABDITIS BACTERIOPHORA

The use of entomopathogenic nematodes (EPNs)as a non-chemical treatment system is one of the most mo-dern techniques promoted by the 2008/128/EC standards for the biological control of plant pathogens. The distri-bution ofEPNscould be carried out with the same sprayers used for the distribution of pesticides. This research is focusedon the effects of the mechanical stress due to hydraulic compression on EPNsItalianstrains,Stei-nernemafeltiaeand Heterorhabditisbacteriophora, to assess their residual strength and vitality under laboratory tests. Liquid suspensions of nematodes were subjected to 8 different levels of hydrostatic pressure from 5 to 40 bar. The hydraulic compression test was conducted through a hydrostatic compression system specifically de-signed for the experimental test. Although correlation curves show an increment of14%in nematode mortality, the statistical analysisdid not show any significant effect of static pressure on the vitality and infectivity of EPNs, that makes them suitable for field application with sprayers. These preliminary positive results on the effects of compression on the viability of EPNsare preparatory to subsequent field tests under high pressure