Chemical Composition of Essential Oil of Ocimum basilicum L. and Its Potential in Managing the Alternaria Rot of Tomato

Abstract

: The essential oil obtained by hydro-distillation of leaves of Ocimum basilicum (basil essential oil) was analyzed for its potential to manage the Alternaria alternata causal agent of Alternaria rot of tomato, in vitro and in vivo. Further, the chemical composition of the extracted basil oil was analyzed by the GC/MS. A total of 20 chemical compounds were identified in the hydro-distilled basil essential oil. The primary constituents of the basil essential oil were methyl chavicol (38.2 %) and linalool (28.7 %). In vitro, the basil essential oil successfully constrained the growth and conidia germination of A. alternata. The highest concentration of basil essential oil (10 %) provided maximum growth reduction (88.0 %) of the fungus. Likewise, the highest concentration of basil essential oil (10 %) caused a 90 % reduction in conidia germination. In vivo, the tomatoes treated with 4 % and 6 % basil essential oil had 33.3 % and 55.5 % respectively, reduction in the infected wounds as compared to control (untreated inoculated). Also, there were 52.9 % and 62.3 % less A. alternata infected fruits when treated with 4 % and 6 % basil essential oil respectively as compared to control (untreated inoculated). This proves that the basil essential oil was able to manage the Alternaria rot of tomato successfully. Therefore, the basil essential oil can substitute the synthetic fungicides to manage the Alternaria rot of tomato.