This research was study the production of essential oil from tobacco leaves for insect repellents. To increase value and development of new products form tobacco leaves. This product is environmental friendly. In this research is divided into two parts: Laboratory scale and get a knowledge to the municipal in Nhongkhai province. Nicotine is an insecticide that effect to insects. This product evaporated pass through natural packaging. A natural packaging can be easily degradation in the environment. Moreover this product also helped to reduce the hazardous chemicals or pesticides usage and not residues for long time.

However recognized as more sustainable and safer way for crop production organic agriculture is still facing many technical difficulties. One of the problems is concerning the management of posthavest disease caused by fungal pathogens. Since the applications of synthetic fungicides are prohibited thus organically produced crops are more vulnerable to be attacked by pathogens. Therefore the development of novel reliable and more compliant technologies for diseases management are required. The aim of this study was to demonstrate the potential use of plant essential oils as biofumigant to control of fungal diseases of tomato during storage. We selected three essential oils including clove oil cinnamon oil and ajowan oil for this study. The in vitro test for antifungal activity showed that the volatile headspace of the three oils exhibited potent effect on the test pathogens which includes Botrytis cinerea Fusaruim oxysporum and Aspergillus niger. Then ajowan oil which showed highest inhibitory effect was further evaluated for its effectiveness when applied as biofumigant. Results from the experiment indicated that fumigation with ajowan oil can reduce the occurrence gray mold decay of tomato (caused by B. cinerea) significantly. The rate of control was up to 100 % during fifteen days of storage at 20 ºC. These results support the idea of using the essential oil as biofumigant for protection of postharvest tomato from fungal diseases. However further comprehensive studies are still required especially on the issues concerning the reliability and eco-efficiency of this method at trial and commercial level.

The purposes of this research were to investigate the factors consisted of a temperature different parts of the lemongrass and a size of chopped lemongrass that affected to distillation of lemongrass essential oils. There are two experiments in this work. The first experiment investigated the factors by defining 1) temperature at 105 oC and 110 oC 2) different parts of the lemongrass (Leaves and trunk) and 3) sizes of chopped lemongrass at 1-2 cm and 15-20 cm respectively. 2k Factorial designs method was used for this experiment. In the second experiment the appropriate parameters from experiment 1 were used for 3 replicates to find an average of lemongrass essential oils. The results of first experimental analysis showed that the appropriate parameters were temperature parts of the lemongrass and sizes of chopped lemongrass at 110 oC leaves and 1-2 cm respectively. For the result of experiment 2 it was found that the average of lemongrass essential oils was 30.36 ml.