Selection of green carrier solvent for the effective creation of bio-inspired liquid formulation and anti-fungal potency evaluation.

Abstract

Existing pesticide formulation solvents generate volatile organic compounds (VOCs), are combustible, and are classed as hazardous air pollutants (HAPs), meaning they are detrimental to users and phytotoxic to crops. Green solvents are required in formulations due to regulations, health, and environmental concerns. In emulsifiable concentration (EC) formulations, the "green chemistry" movement has led to the use of less harmful solvents. After a detailed and comparative fungal growth inhibition assessment, the least harmful carrier solvent among four regularly used organic solvents [dimethyl sulfoxide (DMSO), dimethylformamide (DMF), aromatic hydrocarbon (C9), and methyl oleate] was chosen in this study. We employed methyl oleate (cis-9-Octadecenoic acid methyl ester) as a bio-based green reserver (60%) to create effective bioinspired EC formulations (30%) of Pongamia pinnata L extract utilising emulsifier blends (10 percent) based on the known toxicity order (DMF > DMSO > C9 > methyl oleate). EC1 outperformed the other thirteen formulations (EC1-EC13) in terms of emulsion stability, cold test, accelerated storage stability, flash point, and other metrics, proving its suitability for commercial production. Using four therapeutically appropriate concentrations of agricultural usage, in-vitro fungicidal effects against Alternaria solani and Phytophthora spp. were examined.A. solani (EC50 = 0.08 percent) showed the greatest growth suppression (87.4 percent) at the maximum dosage (1 percent), followed by Phytophthora sp. (71.1 percent) (EC50 = 0.49 percent). The study proved its utility in the production of environmentally acceptable green solvent-based herbal formulations as a long-term crop protection alternative to harmful chemical pesticides.