Biological Control for Inhibiting Fungi Caused Leaf Blight Disease of Eucalyptus

Abstract

The aim of this study was to investigate the inhibition of leaf blight disease of eucalyptus caused by C. reteaudii and Pestalotiopsis sp. using two biological control methods including antagonistic fungi and wood vinegar. Two species of antagonistic fungi, Trichoderma asperellum and T. harzianum, were tested for their ability to inhibit leaf blight disease of eucalyptus by in vitro experiment. Both antagonistic fungi had not significantly different to inhibit the mycelial growth of pathogenic fungi of eucalyptus (P > 0.05). Additionally, T. asperellum was tested for the inhibition of C. reteaudii by directly spraying of the pathogen on the seedlings. It was found that spraying T. asperellum into the soil around the basal stem of seedlings could reduce the percentage of disease incidence comparing with control treatments. Moreover, the spraying T. asperellum every 3 days had the disease incidence lesser than spraying T. asperellum only one time. For using wood vinegar as biological control, it was found that C. reteaudii (IC50 = 13,679.71 ppm) was inhibited better than Pestalotiopsis sp. (IC50 = 18,218.51). Moreover, the mycelial growth of both pathogens were completely inhibited at the concentration 40,000 ppm. Therefore, both biological control methods might be apply for control eucalyptus leaf blight disease caused by C. reteaudii and Pestalotiopsis sp.