It’s all in the dust on the bee’s legs and underside when it emerges from the hive, heading out to pollinate. The bee is loaded with Clonostachys rosea spores, a natural fungus that blocks the development of common diseases like sclerotinia, fusarium and grey mould on flowering crops.
“We have a microbial product that is actually a beneficial fungus, and a dispenser system that uses bees to deliver the product,” says Ashish Malik of Bee Vectoring Technologies International Inc. (BVT) in Mississauga, Ontario. “When bees leave their hive, they pick up this powder that contains the beneficial fungus. When they forage for pollen or nectar, they take the product and leave it on the flower.”
Clonostachys rosea is easily produced in a lab. BVT has developed a unique, patent-pending biocontrol formulation (BVT-CR7), a harmless powder Vectorite™ that adheres to bees as they walk through Vectorpak™ trays each time they leave the hive.
After three to nine days, the depleted trays are replaced quickly while the bees are quiet. Fresh inoculation by Vectorite must continue throughout the flowering season so that each new flower is protected before it can be infected by one or more disease pathogens.
This year, BVT is continuing replicated field trials of both organic and conventional strawberries in Ontario and Florida. The target is grey mould, a common issue in gardens and in fresh fruit from stores. Sunflower trials to control sclerotinia head rot are underway in Ontario, North Dakota and Minnesota. BVT is looking for North American registration, and may be available in Canada for the 2019 crop year.
Malik hopes that BVT will be OMRI Listed for use by organic growers by the end of 2018. “The implications for the organic industry will be dramatic,” he says.
BVT has ramped up quickly since its initial public offering in March 2015, opening a state-of-the-art production and research facility in October in Mississauga. In November, Malik joined BVT as an independent advisor and was promoted to President and CEO in 2016.
Five patent families are being launched worldwide. Registration and licensing applications are underway with the Environmental Protection Agency (EPA) in the United States and with Canada’s Pesticide Management Regulatory Agency (PMRA).
“We have focused on approval from the EPA first as a conventional, mainstream product. We are hoping to launch in the US in 2018,” Malik says. “After that, we will look for organic [certificates] and will start scaling up for global distribution.”
Agricultural technology development is complicated. Using a living, natural, biological agent selected for its ability to prevent infection by common pathogens is even more difficult. It is a departure for Malik and others at BVT. Most come from long careers in the agricultural chemistry industry.
“I came from 14 years on the agri-chemical side and have worked for two of the biggest global multinationals,” Malik says. “I really believe in this bio-technology, and that it has the next level of impact in terms of sustainability for farming.”
Previously, Malik was the Bayer CropScience VP of Global Marketing for Biologics. He managed the biological assets and developed strategies for integrating biologicals with traditional chemical products, seeds, traits, seed treatments and services. Malik serves on the board of the Biopesticides Industry Alliance, holds an MBA from Carnegie Mellon University and a degree in engineering from Swarthmore College.
Roots in Guelph
John C. Sutton, a plant pathologist formerly at the University of Guelph, discovered the beneficial effects of Clonostachys rosea. He specialized in crop disease epidemiology and management. Around 1985, Sutton started looking for a biological agent to control economically important plant diseases. He began with strawberries and grey mould.
“Disease organisms, pathogens, were developing resistance to a lot of the fungicides,” Sutton says. “There was increasing public concern about pesticides and about fungicides getting into foodstuffs and animal feeds. The question was, could we find and use something more natural—such as a biological control agent?”
In 1986, Sutton and his co-workers began a search for all the fungi or bacteria already associated with strawberry plants. The team collected plant specimens from woodlands, fields, home gardens and commercial facilities—anywhere strawberries were growing in Ontario. They isolated each organism they found, ending up with more than 1,400 isolates of bacteria or fungi.
“We screened them all. Initially we put them on tiny bits of leaf tissue, petals and sepals in controlled conditions, at a particular concentration, and challenged them with the grey mould pathogen, Botrytis cinerea,” Sutton says.
In the next phase, some were placed on whole plants in growth rooms and observed for grey mould. Further selections were made, and put into field plots.
One kind of fungus consistently gave a complete, or almost complete, control of the botrytis fungus. Then called Gliocladium roseum, it is now known as Clonostachys rosea. “There turned out to be 12 or 15 isolates of this in our collection,” Sutton says.
Application methods were tested. Preparations were sprayed on foliage, but spraying the entire crop seemed wasteful when flowers were the main pathway for disease organisms. The idea emerged to use bees to deliver, or vector, the fungus directly to flowers. In 1992, using honey bees, Sutton and colleagues were the first to publish this technique.
The professional, peer-reviewed journal Plant Disease published their story in 1997. By then, the researcher had much more information. The selected fungus was effective against botrytis in plants as diverse as strawberry, geranium, tomato and black spruce, and could suppress many other diseases, shielding against fusarium, monilinia, pythium, sclerotinia and other pathogens.
Today, the list of plants it can protect is enormous. Sutton says, “It establishes as an endophyte in every kind of crop plant we’ve looked at—and that must be at least a hundred! For example, it goes into flowers, stems and roots of grasses, tomatoes, peppers, corn, blueberries, almonds, canola, wheat, sunflowers and many greenhouse flowers. To my knowledge, no other fungus on the planet can associate with such a diverse taxonomic group of plants.”
In 2010, Sutton and colleagues Peter Kevan and Todd Mason looked towards commercialization of bee vectoring of biological agents. It took years to formulate and test Vectorite, which contains the fungus spores that protect flowers from disease. It had to meet several requirements:
- The fungal spores had to remain alive.
- The bees needed to maintain their own health.
- It could not be toxic to bees.
- It had to attach to bees.
- Bees needed to pick up enough dust, reliably, so a powder dispenser system was designed for use in hives.
- And, it had to be commercially interesting.
“For many years it was quite difficult to get commercial interest in biological control. Even today, the big companies see their profits more in fungicides than in biological agents,” he says.
Malik and Sutton dislike the terms “fungicide” or “biofungicide” for BVT-CR7, the special strain of Clonostachys employed for bee vectoring. “Those terms have erroneous connotation,” Sutton says. “For the most part, C. rosea doesn’t kill organisms.” Inside the plant tissues as an endophyte, the fungus is in extremely tiny colonies that interact beneficially with the plant. There is no visual evidence that it is present.
However, when a pathogen such as botryt is attempts to attack, “Then C. rosea rapidly grows and occupies the tissues immediately around the pathogen like a shield. As well, it also induces the plant’s natural resistance mechanisms to numerous pathogens,” Sutton says.
Results from 2016
Widely separated trials were done in 2016 and have been increased for 2017.
Near Caledon, Ontario, Davis Feed & Farm Supply received four hives of honeybees and used Vectorite to protect 20 acres of conventional sunflowers. Other hives, without Vectorite, served another 30-acre field a kilometre away.
In both fields, the disease level was negligible in 2016. “This problem with sunflowers, head rot, usually rears its ugly head in wet conditions. We had a very dry summer last year,” says owner John Davis.
The harvest was a big surprise: “We had better yields off the treated sunflowers,” he says. In an average year, Davis harvests 1200 to 1400 pounds of sunflower seed per acre. “The yield off the test group was close to 1800 pounds to the acre. It was about 20 to 25 percent more than the yield in the control group,” Davis says.
The plants were shorter than normal, but the heads were a normal size. Both fields were seeded at 26,000 plants per acre to a new high-yielding variety, Falcon. Both were planted on the May long weekend and both were harvested in the fall within a day or two.
Weed control was “very clean” on the control field, whereas the Vectorite-protected field had infestations of giant ragweed and nightshade. “I thought that would affect the yield in a negative way,” Davis says.
The bees pollinated with BVT-CR7 in the dry conditions. Trays were changed every three days. “Bees would come out covered in dust from top to bottom. When they came back, they’d unload the pollen and walk through this little tray of powder before they left again. It worked very well,” Davis says.
“Later, BVT took off 400 heads to see how much coverage the bees actually did. It was amazing. They had got into the far corners of the field, and dumped the powder on it,” he says. “I’m looking forward to seeing the performance in a year with more moisture.”
US Sunflower Trials
A second sunflower trial was managed by plant pathologist Venkata Chapara at the North Dakota State University (NDSU) experimental research station. This site had a “pretty good” level of infestation. The Vectorite was carried by bumblebees. The trial plots had a wet flowering season and were sprayed with disease spores, to be sure they had headrot disease. For first-year results, disease level index was rated at 12% on the non-treated sunflowers. The disease index level on Vectorite-protected sunflowers was only five percent.
The yield was greater on the BVT plots. Chapara says, “We had 1,880 pounds per acre on the control plots and the BVT plots had 2,053 pounds per acre. That’s a difference of 173 pounds, or a nine percent increase.” NDSU is continuing an expanded trial in 2017.
A third sunflower trial in Minnesota involves industry veteran John Swanson, who has worked 40 years in the sunflower industry, in agronomy, research, product development and sales.
In 2016, Swanson put out 60 hives of bumblebees with Vectorite on eight fields, across about 58 kms. “We started out extremely dry. It stayed dry until l July, then it was extremely wet until harvest. We had 43 inches of rain on several of our fields,” he says. “The night after we first set up the hives, we had a 6-inch rain.”
Swanson felt it wasn’t a good trial. “We didn’t have any yield differences that we could identify. We had almost zero sclerotinia in all locations. Almost all our rains came at night, and every day, we had some sunshine. That’s why we didn’t have the sclerotinia, in my opinion.”
Swanson is skeptical about cures for sunflower diseases. “I’ve tried many things that don’t work but, yes, I will try again in 2017 with both honeybees and bumblebees,” he says. “Either way, in my opinion, Vectorite needs to have a return of $3 or $4 for every dollar invested because you don’t have the disease every year. If it does that, and if we have data that Vectorite works effectively, I think this will take off.”
Back to Strawberries
A few strawberry fields, organic and conventional, were treated with the BVT Vectorite powder in Florida’s winter growing season in late 2016. Grey mould or botrytis is one of the worst diseases for the industry that supplies most of the winter strawberries for North America.
Greg Faust is working to bring the new product to market and coordinates the trials. He has worked in marketing and product management with fungicides and insecticides for 35 years.
“We are into advanced trials this year in Florida. Our objective is to position Vectorite as a foundation system for the season. We put out the bees and Vectorite powder at the start of the season, then maintain that system for the entire season,” Faust says. “The bees continuously deliver the biological agent providing continuous protection against botrytis. Technically, the strawberries don’t need the pollination because they are wind-pollinated, but the BVT product is bringing disease control and a pretty strong vigour effect to the plant and to the field.”
Faust says biological systems have more variables than formulated chemicals with long shelf life and low sensitivity to temperature. “It takes a lot of work. Are the bees out when it’s windy or when it’s cold? What if it’s too hot? What about the effects of a three-day rain? These factors have to be thought through and tested before we bring this to market. Part of the effort is to really work with the growers to design effective protocols that integrate the BVT system into the growers’ overall agronomic systems.”