Canadian Journal of Plant Pathology (2016) 38, 430-439

Wojciech J. Janisiewicz, Fumiomi Takeda, Breyn Nichols, D. Mike Glenn, Wayne M. Jurick and Mary J. Camp (2016)
Use of low-dose UV-C irradiation to control powdery mildew caused by Podosphaera aphanis on strawberry plants
Canadian Journal of Plant Pathology 38 (4), 430-439
Abstract: Strawberry powdery mildew, caused by Podosphaera aphanis, significantly reduces fruit yield and quality and predisposes fruit to other diseases. Fungicides have been routinely used to control this disease; however, their limitations necessitate the development of alternative approaches, especially for protective culture and organic production. A disease-control strategy was developed that combines treating strawberry plants with a low dose of UV-C (low dose/short duration) followed by a specific period of darkness, which greatly increases the lethality of UV-C. A leaf disc assay was developed to evaluate the effectiveness of the UV-C treatment in controlling powdery mildew on strawberry. Irradiation for only 15 s by UV-C lamps with an output of 20.6 µW cm^-2 followed by a 4-h dark period resulted in a significant decrease (P = 0.05) in P. aphanis as determined by the percentage of the leaf disc quadrants colonized by the fungus. An increase in irradiation exposure to 60 s followed by 4-h dark period resulted in complete control of the powdery mildew in most cases. Such treatment of strawberry plants once a week for 3 weeks resulted in more than a four-fold reduction (P = 0.01) of conidial production on adaxial leaf surfaces exposed to the UV-C irradiation, and did not affect leaf photosynthesis (P = 0.05). The UV-C treatment of plants over 15 weeks reduced the amount of diseased fruit and increased fruit yield and quality (P = 0.05).
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Wojciech J. Janisiewicz

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Podosphaera aphanis	Strawberry (Fragaria)