Herbal Plant Crude Extracts and Essential Oils to Control Anthracnose Disease in Dendrobium ‘Earsakul’

The effect of crude extracted and essential oils was compared for controlling anthracnose disease in Dendrobium ‘Earsakul’. Dendrobium ‘Earsakul’ was tested to determine the efficiency of five Thai medicinal herbs: galangal, garlic, lemongrass, turmeric and ginger on the growth inhibition of Colletotrichum sp. as the pathogens of anthracnose or leaf blight disease. Each medicinal plant was blended and macerated in 95% ethyl alcohol and sterile distilled water at ratio 200 g: 400 mL for seven days. Crude extracts and essential oil were tested for inhibition of their antifungal potentials against Colletotrichum sp. by food poison technique. Results in the laboratory and under greenhouse condition showed that 8,000 ppm essential oil of ginger inhibited the growth of Colletotrichum sp. both before and after disease infection at 100% similar with the chemical compound Mancozeb