Preparation of Chitosan–Hexaconazole Nanoparticles as Fungicide Nanodelivery System for Combating Ganoderma Disease in Oil Palm

Abstract

Fungicide is used to control fungal disease by destroying and inhibiting the fungus or fungal spores that cause the disease. However, failure to deliver fungicide to the disease region leads to ineffectiveness in the disease control. Hence, in the present study, nanotechnology has enabled the fungicide active agents (hexaconazole) to be encapsulated into chitosan nanoparticles with the aim of developing a fungicide nanodelivery system that can transport them more effectively to the target cells (Ganoderma fungus). A pathogenic fungus, Ganoderma boninense (G. boninense), is destructive to oil palm whereby it can cause significant loss to oil palm plantations located in the Southeast Asian countries, especially Malaysia and Indonesia. In regard to this matter, a series of chitosan nanoparticles loaded with the fungicide, hexaconazole, was prepared using various concentrations of crosslinking agent sodium tripolyphosphate (TPP). The resulting particle size revealed that the increase of the TPP concentration produced smaller particles. In addition, the in vitro fungicide released at pH 5.5 demonstrated that the fungicide from the nanoparticles was released in a sustainable manner with a prolonged release time up to 86 h. On another note, the in vitro antifungal studies established that smaller particle size leads to lower half maximum effective concentration (EC50) value, which indicates higher antifungal activity against G. boninense.

Enhanced fungicidal efficacy onGanoderma boninenseby simultaneous co-delivery of hexaconazole and dazomet from their chitosan nanoparticles

“…14 The relationship between the hydrodynamic mean particle size distribution and HRTEM mean particle size distribution of the synthesized chitosan-hexaconazole-dazomet nanoparticles to (A) their percentage inhibition at 50 ppb and (B) the calculated EC 50 (ppb) value on G. boninense. In comparison to our earlier work on single loaded systems of hexaconazole 29 and dazomet 30 into the chitosan nanoparticles, the results revealed a synergistic effect in the codelivery of hexaconazole and dazomet in the inhibition of G. boninense growth. The lowest EC 50 values achieved for single loaded hexaconazole and dazomet in chitosan nanoparticles at 20 mg mL À1 of TPP were 4.6 AE 1.6 and 13.7 AE 1.8 ppb, respectively.…”

“…Hexaconazole-dazomet-loaded chitosan nanoparticles were prepared using ionic gelation method. 29,30 Briey, 5 mg mL À1 of chitosan was prepared in 100 mL of a 1.0% (v/v) acetic acid solution and, in a different ask, 10 mg mL À1 of hexaconazole and dazomet were prepared in 100 mL of DMF separately. Then, all the solutions were mixed together under stirring until a homogeneous solution was obtained.…”

Green-Synthesization of Silver Nanoparticles Using Endophytic Bacteria Isolated from Garlic and Its Antifungal Activity against Wheat Fusarium Head Blight Pathogen Fusarium graminearum

“…Various metals nanoparticles have been widely applied in agriculture due to their distinctive features such as antimicrobial activity, catalytic activity, magnetic and electrical properties [11,12]. Furthermore, several studies have demonstrated that metal nanoparticles have been well documented as fungicides [10,13].…”

Chitosan-Based Agronanochemicals as a Sustainable Alternative in Crop Protection

“…The slightly acidic environment of the intracellular medium is also reported to be able to help release Zn from chitosan nanoparticles. Chitosan-hexaconazole nanoparticles and chitosan-dazomet nanoparticles demonstrated diffusion-controlled release of the fungicides at pH 5.5 with half release times (t 1/2 ) of 42 and 11 h, respectively [28,29]. Moreover, the co-release of hexaconazole and dazomet from the chitosan-hexaconazole-dazomet nanoparticles prolonged the release time with t 1/2 of 53 and 15 h, respectively [30].…”