Chemical Variation and Implications on Repellecy Activity of Tephrosia vogelii (Hook f.) Essential Oils Against Sitophilus zeamais Motschulsky

Abstract

Chemical variability in the components of T. vogelii essential oils from eastern Uganda was identified using principal component analysis (PCA) and Agglomerative hierarchical clustering (AHC). Based on the profiles of the compounds of farnesene family three chemotypes were found: farnesol (chemotype 1), springene (β- Springene and α-Springene) and the β-Farnesene were distinctive in chemotype 2 and a mixed variety of farnesol and the Springene. In the three cases, alkybenzenes; o-xylene, m-xylene and ethylbenzene were significant components in the oil. 1,4-dihydroxy-p-menth-2-ene, 5,9-undecadien-2-one, 6,10-dimethyl, and 3-cyclohexen-1-carboxaldehyde,3,4-dimethyl were other prominent constituents. The yields of the essential oils did not vary significantly however the chemical composition varied with harvesting time during the rainy and dry seasons. In choice repellency tests, chemotype 1 and chemotype 2 were more active against Sitophilus zeamais than mixed chemotype. Farnesol was found to be effective only at a higher concentration as a repellent against S. zeamais. However, further study that aims to optimize and standardize the varieties and harvesting period needed for recommendation to smallhold farmers.

Field Efficacy of a Biopesticide Based on <i>Tithonia diversifolia</i> against Black Sigatoka Disease of Plantain (<i>Musa</i> spp., AAB)

“…Indeed, T. diversifolia contribute to plant protection by modifying the microbial community and stimulating plant defense mechanisms [14]. Moreover, this biopesticide based on T. diversifolia contains many minerals and secondary metabolites such as nitrogen, phosphorus, potassium, magnesium, proteins and phenolic compounds (alcaloids, sesquiterpens, lactones and flavonoids), involved in different physiological role in the plant [10] [11] [12]. In addition, defensive metabolites have been shown acting on the susceptible Musa spp.…”

“…T. diversifolia biopesticide could be a solution to this problem since it is both less restrictive for the producer, and preserver of the environment and human health. Indeed, it contains many minerals and some secondary metabolites like alkaloids, flavonoids and terpenoids [10] [11] [12]. Moreover, recent studies have highlighted the fertilizer, the protective, the insecticide and the fungicide effects of aqueous extract of T. diversifolia on different plants [13] [14].…”

Evaluation for Feeding Deterrents Against Sitophilus zeamais (Motsch.) from Tithonia diversifolia (Hemsl.) A. Gray

“…The methodology reported by Kerebba et al 4 was used without modification. GC analysis was done using Brunker 300 Gas Chromatograph equipped with FID detector and ZB-5 column (30 m in length × 0.25 mm i.d × 0.25 µm film thickness).…”

<i>Tithonia diversifolia</i> Leaves and Stems Use as Substrate Amendment Promote the Growth of Plantain Vivoplants in the Nursery

“…T. diversifolia plays an important role in crops nutrition and control due to its biofertilising and antifungal properties respectively [1] [2] [3] [4]. Indeed, it is rich in nutrients, such as nitrogen, phosphorus and potassium; and defense metabolites, such as flavonoids, tannins, alkaloids, PR-proteins for plants defense [1] [7]. The leaves, the stems, and the roots of T. diversifolia also contain some phytochemicals such as sesquiterpenoids, diterpenoids, alkaloids, flavonoids, chlorogenic acid derivatives, phenols, saponins, tannins and terpenoids [6] [7].…”

“…Indeed, it is rich in nutrients, such as nitrogen, phosphorus and potassium; and defense metabolites, such as flavonoids, tannins, alkaloids, PR-proteins for plants defense [1] [7]. The leaves, the stems, and the roots of T. diversifolia also contain some phytochemicals such as sesquiterpenoids, diterpenoids, alkaloids, flavonoids, chlorogenic acid derivatives, phenols, saponins, tannins and terpenoids [6] [7]. T. diversifolia decomposes rapidly after application as a soil amendment to maintain and improve the physical, chemical and biological properties of the soil and also increase the availability of nutrients [5].…”