Organic extracts for fall armyworm (Spodoptera frugiperda) control in native corn (Zea mayz L.)

Abstract

Objective: Determine the incidence of fall armyworm in corn plots and evaluate the insecticidal effect of garlic extract and rue essential oil and understand their phytochemistry.

Design/methodology/approach: The fall armyworm incidence was determined through the “five of golds” systematic sampling, composed of 20 plants per sampling point (100 plants in each plot). This assessment was conducted in 15 plots of native corn in the municipality of Cherán, Michoacán. Control bioassays were also tested, in the laboratory and field; where rue essential oil, garlic extract, cypermethrin, and an absolute control (water) were evaluated.

Results: The highest fall armyworm incidence (18%) occurred in a corn plot at Andasticua. In the laboratory, cypermethrin induced the highest fall armyworm mortality (100%), followed by rue essential oil (83%). In the field, both the insecticide and the rue essential oil reduced lepidopteran incidence. The main component of the essential R. graveolens oil is the semivolatyl cinnamoyl chromen (IUPAC name: 2-(3-phenylprop-2-enoyl)chromen-4-one).

Limitations of the study/implications: The present research has no major limitations.

Findings/conclusions: Both products, cypermethrin, and rue essential oil, effectively control fall armyworms in the laboratory and the field environments.