Assessing the insecticidal effect of Citrus aurantium and Nerium oleander extracts and basalt "Farina di Basalto®" as biological alternatives to control Aphis punicae and Planococcus citri in an organic pomegranate orchard

Abstract

This study aims to evaluate the efficiency of basalt with two botanical aqueous extracts of Citrus aurantium and Nerium oleander (50g/L) against Aphis punicae and Planococcus citri in an organic pomegranate orchard. Basalt was applied as a foliar spray with two doses (1.5% and 3%), in the ground as a fertiliser (1.5%), and as a combined application (1.5%). Phenolic compounds of both plants were identified by HPLC-PDA/ESI-MS analysis. Seven and six flavonoids were detected in C. aurantium and N. oleander extracts, respectively. Hesperidin was more abundant in C. aurantium extracts; however, N. oleander extracts contained more quercetin rutinoside. A. punicae populations were significantly higher in control trees compared to the treated ones. A. punicae mortality rates reached high values above 90% for basalt and plants extracts and efficacy rates exceeded 80%. P. citri mortality rates reached 88% and 77%, and efficacy rates exceeded 75% and 66% for basalt and plant extracts, respectively. These findings may help to plan Integrated pest management strategies in organic orchards to avoid toxic chemical pesticides.

Keywords

• basalt
• biological control
• extracts
• efficacy rate
• hplc
• mortality rate