Novel Biofungicide Approved for Grapes, Leafy Greens
Marrone Bio Innovations, Inc. (MBI) has received approval from EPA on its newest biological fungicide, Stargus. This product is the sixth product commercialized by MBI in only 11 years.
The product is based on a new strain of Bacillus amyloliquefaciens discovered by MBI, targeted to downy mildews, white molds, Botrytis gray mold, and bunch rot. The fungicide also controls pathogenic soil fungi, including diseases such as Fusarium and Rhizoctonia, as shown in field trials in the U.S., Canada and Europe.
Stargus is the new brand name and will be focused on specialty crops such as grapes and leafy greens. It will also be labeled for use on root and bulb vegetables such as potatoes, carrots and onions. MBI expects first sales when state registrations are granted.
MBI says growers have few choices of products that perform well on the group of fungi that cause downy mildews on grapes, potatoes, leafy greens, and other crops, as well as white molds on leafy greens, succulent and dry beans. Adding to the challenge, these crop disease-causing plant pathogens have also developed resistance to major chemistry classes of conventional pesticides.
Stargus is the result of MBI’s directed screening discovery program to find a solution that addresses such a specific market need. This product is also complementary and additive to the broad spectrum of diseases covered by MBI’s first biofungicide, Regalia, providing a solid one-two punch to a broad spectrum of plant pathogens. MBI and partners also are testing this Bacillus-based product for seed treatment applications.
“We knew that new solutions for downy mildews were badly needed, so our team of scientists set out to find one,” said Dr. Pam Marrone, MBI’s Founder and CEO. “Our screening platform tested more than 16,000 microbes against important plant pathogens and discovered this novel candidate with a broad spectrum of performance and stand-out activity against downy mildews, Botrytis gray mold/bunch rots and white molds. This is the sixth EPA-registered product that MBI has brought to market on only 11 years, which is an unparalleled accomplishment.”
Tests conducted at MBI’s research and development lab show that Stargus works by colonizing plant root hairs, leaves and other plant surfaces thereby preventing establishment of fungal and bacterial pathogens, including Fusarium, Sclerotinia, Botrytis, Rhizoctonia, and Sclerotium. Additional R&D indicates that the bacterium also produces natural compounds, some of which inhibit bacterial and fungal mycelial growth, as well as spore germination.
In addition, the bacteria trigger systemic acquired resistance and induced systemic responses in the plant, creating a healthier and stronger plant to ward off diseases and increase growth and yield. MBI has been issued a patent on the novel strain used in Stargus.
Field studies showed efficacy against downy mildew, Botrytis bunch rot and black rot on grapes; downy mildew on cucurbits; pink rot, white mold, and late blight on potatoes; Cercospora leaf spot on sugar beets; Fusarium of tomato and celery; and white mold on soybean, sunflower, beans, lettuce and canola; and soil applications on potatoes for control of Rhizoctonia and Phytophthora eurythroseptica (pink rot). MBI also is testing for seed treatment applications and is investigating applications for turf and ornamental markets. Successful field trials have been conducted in the United States, Mexico, Canada and Europe.
The biofungicide product has been submitted to Canada and Mexico for approval and the dossier is being prepared for Europe, which has the largest market for grape downy mildew products. In France, depending on the year, production of grapes has been estimated to be reduced by as much as 50% from downy mildew.