The Environmental Protection Agency has approved major label changes to Regalia, a biofungicide from Marrone Bio Innovations of Davis, Calif.

The label now covers use of the product to fight several soil-borne pathogens, including Rhizoctonia, Pythium, Photophthora and Fusarium, according to a news release.

The biological fungicide also can be applied through drip irrigation, according to the new label.

The active ingredient in Regalia is an extra from giant knotweed, Reynoutria sachalinensis.

It works by switching on plants' natural defenses, which prompts them to produce higher levels of natural proteins that inhibit disease development, according to the release.