Compatibility of Crown Flower Extract (Calotropis gigantea L.) and Aspergillus sp. to control Spodoptera exigua Hubner on Shallot Crops

Abstract

Biopesticides are strongly recommended in pest management to mitigate the harmful effects of the chemicals. This study aimed to evaluate the combined effect of the crown flower extracts (CFE) and Aspergillus sp. in controlling Spodoftera exigua, a major pest of shallot. Three level concentrations of CFE (g/l) i.e. 0 (C0), 2.42 (C1), and 4.84 (C2), as well as Aspergillus sp., i.e. 0 % (A1), 0.5% (A1), and 1.0% (A2), were combined and set up in a Randomized Complete Block. Pest infestation and shallot yields were observed to assess the effectiveness of those biopesticides. The results showed that the application of CFE or Aspergillus sp. was more effective in suppressing the infestation of S. exigua than without biopesticides. However, the highest concentration of the combination of both biopesticides results in the best treatment, possibly suppressing the beet armyworm infestation by about 31,09 % compared to the control. It has the lowest values of the Area Under Pest Damage Curve (AUDPC) and the highest yield of shallots (5.50 t/ha). The study confirmed that a combination of CFE and Aspergillus sp. was suitable for managing S. exigua on shallot crops and supporting the integrated pest management of beet armyworms.