The objective of this research was to evaluate the influence of spraying pressurization upon the viability of the following entomopathogens microorganisms: the fungus Metarhizium anisopliae, the bacterium Bacillus thuringiensis var. kurstaki, the nucleopolyhedrovirus of Anticarsia gemmatalis (AgMNPV), and the nematode Steinernema glaseri. The sprayer hydraulical system was used without filters and equipped with JA-2 hollow-cone nozzle type. The experimental design was completely randomized, with seven treatments: pressurization of spraying suspension at 172; 345; 517; 689; 1,034 and 1,379 MPa, and check (suspension not submitted to the pressurization). Evaluation of the viability of M. anisopliae was estimated by the percentage of germinated conidia. For B. thuringiensis, by the number of colonies formed. Efficiency on AgMNPV was estimated indirectly, by means of mortality caused to A. gemmatalis infected as early third-instars larvae reared in an artificial diet impregnated with the viral suspension. For the experiment with S. glaseri it was calculated the percentage of live specimens on Peters slide-blade. It concluded that the entomopathogens M. anisopliae, B. thuringiensis, AgMNPV and S. glaseri can be sprayed up to the pressure of 1,379 MPa without losing the viability of those organisms as biological control agents.
application technology; biological control
