Evaluation of Nanoemulsion Concentrate Botanical Fungicide from Neem, Citronella and Eugenol Oil Using Palm Oil Based Surfactant

Abstract

Pathogenic fungi has became a problem and caused crop failure. Synthetic fungicide was commonly used to control the growth of the fungi, however it has an adverse effect which can pollute the environment. As an alternative, botanical fungicide can be used as antifungal agent which is safer for environment. Neem oil has been reported as inhibitor for pathogen fungi, while eugenol and citronella oil have been proved to have antifungal effect against Aspergillus Niger. The essential oil does not dissolved naturally in water, therefore it is important to formulate this oil using palm oil based surfactant in order to form water dispersed formulation which might enhance the effectiveness of the formulation. This study investigate the best emulsifiable concentrate (EC) formulation using palm oil based surfactant and also the residue in water and soil in order to ensure that the formulation is safe for environment. Nanoemulsion was prepared by mixing essential oil and surfactant with ratio of 60:40, 70:30, 80:20, 90:10 each. The stability was investigated by observing creaming height and particle size overtime. The residue evaluation was done by analyzing TSS, TDS, COD value for water residue and GCMS analysis for soil residue. The best formulation was achieved with composition of neem, eugenol and citronella by 33% each, surfactant MES 20%, PDO 10% and PMO 70% with oil/surfactant ratio 60/40 and solvent ethanol ratio 1:2. The droplet size ranged between 350-480 nm and polydispersity index 0.3-0.5. This fungicide formulation also considered allowable by regulatory standard where the value of TDS was in range 1-100 mg/l, TSS 0-04 mg/l, COD 30-1270 mg/l and pH was in range 5-5.7. The result of Soil residue analysis shows that the essential oil derivatives still remain in soil for five days. It is expected that this result can become reference for fungicide companies and other related stakeholder to formulate stable botanical fungicide.