Effect of essential oils of <i>Thymus vulgaris</i> and <i>Mentha piperita</i> on the control of green mould and postharvest quality of <i>Citrus Sinensis</i> cv. Valencia

Abstract

One of the modern techniques used to control pests and diseases, especially to produce organic crops is to use natural or growing material and components with microbial and herbaceous origin. The aim of this study was to evaluate the effect of natural components on green mould control and the improvement of postharvest fruit quality. The experimental design was completely randomized design with 3 replications. Natural essential oils were obtained from two plants, thyme and peppermint, in 5 concentrations of 0 (as control), 100, 300, 500 and 1000 ppm, and performed in inoculated and noninoculated “Valencia” orange. The results showed that peppermint and thyme essential oils (1000 ppm concentration) decreased decay (27%), compared to the control (100%) in inoculated group. The highest level of vit.C (54.93 mg) was observed in thyme treatment (1000 ppm). TA content had shown significant difference in inoculated and non inoculated fruits affected by treatments. The highest total acid value was observed in non- inoculated fruits of thyme treatment with 100 ppm concentration (1.49 mg). The highest soluble solid content was observed as 11.75Brix in the control without inoculation. Generally, results showed that thymus essential oils have high fungicides to control fungus disease of citrus crops, but need more research to achieve appropriate formulation.

Key words: Essential oils, thyme, peppermint, green mould, shelf life, citrus.