The present invention relates to a method for reducing the total number of pathogens of one or more pathogen living in turf. This invention provides a number of devices to safely deliver the UV light to plants. In one embodiment, the device is made of a plurality of UV emitting devices imbedded in a face of a stationary bed knife blade. The plurality of UV emitting devices forming an arc of substantially continuous UV coverage. This modified bed-knife can be incorporated into a lawn mower to provide UV radiation, while at the same time cutting the turf.
