Kentucky State University
Organic Pesticides from Hot Pepper Extracts
Institution
Kentucky State University
Faculty Advisor/ Mentor
George F. Antonious; Tejinder S. Kochhar
Abstract
Many studies have indicated potential ecological damage due to the widespread use of synthetic pesticides. Basic and applied research to provide alternative pesticides with low impact on human health and environmental quality is needed. This investigation was designed to: 1) test the toxicity of new hot pepper fruit extracts to cabbage looper larvae; 2) test the repellency of new hot pepper fruit extracts to spider mites; 3) characterize the biochemical composition of hot pepper fruit extracts for potential identification of compounds responsible for toxicity and/or repellency; and 4) select candidate hot pepper accession(s) producing most effective (toxic and/or repellent) phytochemicals for use as pest control agents. Crude extracts of hot pepper accessions of Capsicum chinense, C. frutescens, C. baccatum, and C. annum were prepared using methanol and analyzed for pentadecanoic acid methyl ester, hexadecanoic acid methyl ester, and octadecanoic acid methyl ester. Bioassays of pure standards of decanoic acid methyl esters using cabbage looper, Trichopulsia ni larvae have shown that pentadecanoic acid methyl ester was the most effective (74% mortality) compared to hexadecanoic and octadecanoic acid methyl esters. Concentrations of decanoic acid methyl esters varied among hot pepper accessions. Accessions PI-632921 (C. annuum), PI-257051(C. frutescens), and PI239703(C. frutescens) contained the highest concentration of pentadecanoic acid methyl ester (827.5 µg/g), hexadecanoic acid methyl ester (969.7 µg/g), and octadecanoic acid methyl ester (1546.6 µg/g), respectively. This research provides an option for organic growers who are seeking alternative to synthetic pesticides.
Organic Pesticides from Hot Pepper Extracts
Many studies have indicated potential ecological damage due to the widespread use of synthetic pesticides. Basic and applied research to provide alternative pesticides with low impact on human health and environmental quality is needed. This investigation was designed to: 1) test the toxicity of new hot pepper fruit extracts to cabbage looper larvae; 2) test the repellency of new hot pepper fruit extracts to spider mites; 3) characterize the biochemical composition of hot pepper fruit extracts for potential identification of compounds responsible for toxicity and/or repellency; and 4) select candidate hot pepper accession(s) producing most effective (toxic and/or repellent) phytochemicals for use as pest control agents. Crude extracts of hot pepper accessions of Capsicum chinense, C. frutescens, C. baccatum, and C. annum were prepared using methanol and analyzed for pentadecanoic acid methyl ester, hexadecanoic acid methyl ester, and octadecanoic acid methyl ester. Bioassays of pure standards of decanoic acid methyl esters using cabbage looper, Trichopulsia ni larvae have shown that pentadecanoic acid methyl ester was the most effective (74% mortality) compared to hexadecanoic and octadecanoic acid methyl esters. Concentrations of decanoic acid methyl esters varied among hot pepper accessions. Accessions PI-632921 (C. annuum), PI-257051(C. frutescens), and PI239703(C. frutescens) contained the highest concentration of pentadecanoic acid methyl ester (827.5 µg/g), hexadecanoic acid methyl ester (969.7 µg/g), and octadecanoic acid methyl ester (1546.6 µg/g), respectively. This research provides an option for organic growers who are seeking alternative to synthetic pesticides.