Insecticidal and Antifungal Activities of Cymbopogon Citratus Essential Oil Against Tuta absoluta and Geotrichum Candidum on Tomato

EasyChair Preprint no. 10923

Abstract

Tomato (Solanum lycopersicum L.) is the world’s most consumed vegetable. In Cameroon, it is the most cultivated vegetable and the second most produced fruit. However, a decline in yield is recorded in Cameroon due to bug infestations, such as Tuta absoluta, which has favored tomato rot caused by Geotrichum candidum. The most common method for pest management is the application of synthetic pesticides which have toxic effects. Therefore, alternative strategies based on the use of natural products as essential oils have shown promise. The purpose of this study was to determine the insecticidal and antifungal activities of essential oil from Cymbopogon citratus. Hydrodistillation was used to extract the oil. The insecticidal activity of the oil was determined by ingestion against Tuta absoluta larvae. Geotrichum candidum was isolated from rotten-infected fruits perforated by Tuta absoluta, and were characterized. Essential oil was tested for antifungal activity through the microdilution method. The results showed that oil exerted insecticidal efficiency with LD₅₀ and KD₅₀ values of 29.762 µL/mL and 27.499 µL/mL, respectively. The oil lengthened pupal duration compared to the controls. Molecular identification confirmed the identity of the pathogens as isolates of Geotrichum candidum. Essential oil inhibited the germination of pathogen conidia with minimal inhibitory concentrations from 0.71 µL/mL to 5.67 µL/mL. This study reports for the first time the insecticidal potential of the ingestion toxicity of Cymbopogon citratus oil against Tuta absoluta. Thus, Cymbopogon citratus oil could be used in the control of Tuta absoluta and Geotrichum candidum. Then, the insecticidal and antifungal activities of this oil should be investigated under greenhouse and field conditions.

Keyphrases: Cymbopogon citratus oïl, Geotrichum candidum, insecticidal and antifungal activities, Tomato, Tuta absoluta

@Booklet{EasyChair:10923,
  author = {Marie Danièle Tchonang Ngongang and Pierre Eke and Modeste Lambert Sameza and Lile Christère Nguemnang Mabou and Madeleine Nina Love Ngo Mback and Champlain Djiéto-Lordon and Fabrice Fekam Boyom},
  title = {Insecticidal and Antifungal Activities of Cymbopogon Citratus Essential Oil Against Tuta absoluta and Geotrichum Candidum on Tomato},
  howpublished = {EasyChair Preprint no. 10923},

  year = {EasyChair, 2023}}