Can fungal epiphytes reduce disease symptoms caused by Phytophthora ramorum?

• Published in: Biological control Vol. 65; no. 1; pp. 135 - 141
• Main Authors: Widmer, Timothy L., Dodge, Stephen C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2013; Elsevier
• Subjects: aerial parts; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; application timing; Applied ecology; Biological and medical sciences; biological control; culture media; disease control; dose response; Epiphytes; foliar application; Fundamental and applied biological sciences. Psychology; fungal antagonists; fungal diseases of plants; host-pathogen relationships; leaves; Metarhizium anisopliae; necrosis; ornamental plants; Ornamentals; Penicillium; Penicillium daleae; Phytopathology. Animal pests. Plant and forest protection; Phytophthora; Phytophthora ramorum; plant pathogenic fungi; Ramorum blight; Rhododendron; signs and symptoms (plants); soil fungi; Sudden oak death; Sudden oak death; Ornamentals; Epiphytes; Phytophthora ramorum; Ramorum blight; Stramenopila; Plant pathogen; Disease; Biological control; Sudden death; Epiphyte; Ornamental crop; Oomycota; Symptomatology; Fungus
• ISSN: 1049-9644; 1090-2112
• DOI: 10.1016/j.biocontrol.2013.01.006

[Display omitted] ► Selected fungi demonstrate antagonism towards Phytophthora ramorum. ► Fungal epiphytes reduce necrosis on rhododendrons caused by P. ramorum. ► A method was developed to screen fungi in planta for biological control of P. ramorum. Leaf infection of ornamental species by Phytophthora ramorum has a significant impact on the spread of this disease. Fungicides have had limited success at controlling this disease. With increasing concerns that repeated fungicide applications will exacerbate the potential for fungicide resistance and mask symptoms, alternative control measures are desired. The potential of biological control has not been thoroughly examined. Fungi, isolated from soil, were screened in dual culture with P. ramorum for antagonistic activity. Three isolates, identified as Penicillium daleae, Metarhizium anisopliae, and Penicillium herquei, were selected for further testing on the aerial plant parts of rhododendrons. Different factors, including culture age, application timing, dose response, and additives in the formulation were studied to determine their effects on the antagonists to reduce leaf necrosis. Although responses were variable for the different antagonists, this study showed that fungi applied to the leaf surface could reduce necrosis caused by P. ramorum. The method developed can be used for screening potential antagonists in planta.