Tuta absoluta is a devastating pest of tomato crops. Currently, T. absoluta control is mainly based on chemicals control. However, these products have a harmful impact on environment. This work aims to evaluate the preventive and curative effect of P. fluorescens Q036B, P. fluorescens Q110B and P. putida (Q172B and Q110B) against T. absoluta.
Materials and Methods
The three strains were tested directly on mortality of Tuta absoluta adult. Indeed, the effect on larva was done on both sides as a preventive and curative trials. Each bacteria suspension was tested at 108 CFU mL–1. The mortality rate was recorded 24-120 h after application.
The results indicated that all tested bacterial isolates has a toxic effect on T. absoluta larva and adults. Within the 24-120 h of exposition period, T. absoluta mortality rates up to 81% for adults and to 100% for larva for Q110B and Q036B isolates, respectively. The Q036B isolates induced higher mortality rates than Q172B and Q110B in both preventive and curative control. Regarding the mechanism of action, all isolates produced hydrogen cyanide, siderophores in addition to the exhibited protease and cellulose activities, while only Q036B and Q172B possess chitinase activity.
The results concluding that the P. fluorescens Q110B and P. fluorescens Q036B were a promising candidates bio-agent for biological control of T. absoluta and has potential to be an efficient component in an integrated pest management program. Then the fruits produced will be qualified as safe for consumers and the environment.