Encapsulation of Ruta essential oil in chitosan and alginate matrices as an ecological alternative for the control of nematodes

Abstract

Controlled release formulations of Ruta essential oil obtained by ionic gelation were developed. The presence of rue essential oil in the alginate and chitosan capsules was evidenced by Fourier transform infrared spectroscopy and differential scanning calorimetry. Release studies revealed that in acidic conditions (pH 4.2), the CHS-REO particles reached a Sw of 240% (w/w) in 30 days and 101% (w/w) for ALG-REO particles, generating a RR of 23.7% for CHS-REO and 20.4% for ALG-REO. On the other hand, at pH 6.8 it favored the Sw for ALG-REO 840% (w/w) and therefore the RR (45.6%) and disfavored the Sw of CHS-REO generating low RR (16.9%). Encapsulated rue essential oil showed equal or superior nematicidal activity against the nematode Melodogyne ssp., compared to free oil and a synthetic nematicide such as Carbofuran, without having a phytotoxic effect on the plant. This study revealed that REO encapsulated in biopolymeric matrices can be used as new nematicide formulations.