Kharbanda, Senior Scientist, Alberta Research Council
Fairy Ring Solution
matter how well you tend your lawn, you've probably been confounded at
least once by the appearance of a fairy ring. The telltale circle of
mushrooms eventually leaves a ring of dead grass. And there never seems
to be a cure. Until now, that is. While researching the fungus that
causes blackleg in canola, Prem Kharbanda accidentally came across
bacteria in a soil sample from central Alberta that not only stopped
black leg in its tracks, it also disabled fairy ring. At an unlikely
research plot along 91 street between 34th and 36th avenues on
Edmonton's south side, Prem is experimenting with the bacteria to
determine the most effective way to administer it to the soil to kill
Intro: They’re the bane of anyone who likes a nice green lawn out front. Now a little bacteria from Sedgewick may be the final answer in cures for fairy rings.
Trying to cure fairy rings is the stuff of old wive’s tales from boiling water, bleach, digging. The list goes on and on. Yet nothing seems to work for very long until now that is. There’s a little bacterium lurking in the soil that Prem Kharbanda is testing and the site this Senior Scientist from the Alberta Research Council has chosen for his experiments couldn’t be more perfect if not unusual. It’s a strip of fairy ring infested boulevard along 91st Street at 36th Avenue, in Edmonton.
PK: It’s very difficult to create fairy rings artificially and this is a natural setting and the fairy rings are quite severe in this area and is good as a natural spot to test our bacterium.
CC: WHY ARE FAIRY RINGS SUCH A PROBLEM?
PK: First of all because fairy rings kill grass and it doesn’t look very good to the homeowners and they’re ugly spots in the lawns. Besides that if people can live with the fairy rings, then there’s not a problem. Once the grass is dead, other unwanted grasses like quack grass and other weeds can take over and that is a problem for the homeowners.
CC: FAIRY RINGS HAVE STYMIED PEOPLE FOR SUCH A LONG TIME. NOBODY CAN SEEM TO COME UP WITH SOMETHING THAT GETS RID OF THEM AND YET THIS IS SOMETHING THAT YOU’RE WORKING ON. WHAT EXACTLY IS IT THAT YOU’RE EXPERIMENTING WITH?
PK: Well, at the Alberta Research Council we always try very innovative and environmentally friendly methods to control diseases and other pests. Here we are using a bacterium that we found locally, in local soils here, and we are trying to use this particular bacterium to kill the fairy ring fungus.
CC: WHERE DID YOU FIND THIS? HOW DO YOU FIND SOMETHING LOCALLY?
PK: Well, while I was working with canola diseases, like blackleg of canola, and a few samples came from Sedgewick. And, we found this particular bacterium inhibiting the blackleg fungus in our petri plates. So we tried this particular fungus against many other fungi and we found it was inhibiting many more fungi than just the blackleg fungus. And, that’s how we found this particular bacterium.
CC: WELL WHAT MADE YOU THINK THAT YOU WOULD TRY IT AGAINST A FUNGUS OR EVEN FAIRY RING?
PK: Well, one of the commercial growers of edible mushrooms, they approached us that they had a problem with their mushroom growing because a lot of other fungi were killing their mushrooms. And, they approached us that whether we could try out our bacterium which is environmentally friendly to control the diseases in mushrooms. So we tried our bacterium in that setting and rather killing those fungi, our bacterium also killed the mushrooms. And from that one we got the idea maybe if this particular bacterium is killing the edible mushrooms, it should kill the unwanted mushrooms in the fairy ring situation.
CC: YOU’RE TRYING IT OUT NOW ON FAIRY RINGS HERE IN THE CITY OF EDMONTON. HOW EXACTLY ARE YOU USING IT?
PK: Well, we are using this particular bacterium in several different ways. First of all, we are using it along with the compost. The compost works as a carrier for this particular bacterium and also provides some food material for this bacterium so this is one treatment that we are using along in compost. Second treatment that we are using is in a surfactant solution. We are putting it, this particular bacterium, in spore forms in the surfactant solution and applying to the fairy rings. That’s one of the things we are trying to research on that how many times it would be necessary to apply during the season that would kill this particular fungus and it will relieve the problem. We will be applying in this particular experiment once a month and perhaps a total four applications will be made this year.
CC: NOW YOU’VE CUT A SAMPLE OUT OF THE SOIL. CAN YOU SHOW ME WHAT THIS IS? WHAT ARE THESE WHITE THINGS DOWN HERE?
PK: Well this is the fungus that causes fairy rings. The fungus starts in the thatch layer in one circular spot and slowly it starts increasing outward and it increases up to thirty centimeters in many cases and it forms a network of mycelium or the fungus itself and it is such a dense fungus that makes it impossible for the water to go down to the roots of these grasses and makes it very hydrophobic layer by which the water cannot percolate any further and because of lack of water, the grass dies.
CC: HOW DO YOU KNOW THAT THIS ACTUALLY GOING TO WORK?
PK: First of all, our bacterium is effective against this particular fungus. In a petri plate it inhibits the fungus which is called and it does inhibit the growth of the fungus under laboratory conditions. But another important thing is that we know that this particular bacterium is effective against several other fungi. And so it has the upper hand in a way that because it has a wide spectrum, it controls several fungi. It may not only control this particular fairy ring but also many other diseases also and perhaps it will give the sod or the grass a chance to survive in the absence of other fungi as well.
CC: WHAT’S THE MECHANISM? HOW DOES IT ACTUALLY WORK IN ORDER TO FIGHT THE FAIRY RING?
PK: Well one method that we think it works is because it release a metabolite which inhibits many fungi. Actually we have isolated the metabolite and that metabolite has been characterized now. And that metabolite is quite toxic to many, many fungi. And when the bacterium multiplies in that multiplication process, it does release that particular metabolite which kills many fungi.
CC: WHEN DO YOU THINK WE MIGHT SEE THIS ON THE MARKET?
PK: Well it will take at least two or three years before we can confirm our results here and after that maybe take another couple of years before it can pass through the federal government registration as a pesticide. So, we will, if we want to use it as a pesticide, perhaps we can call it as a growth promoter and get it to the market earlier.
CC: THANK YOU VERY MUCH
PK: Thank you
Dr. Prem Kharbanda is a Senior Scientist with the Alberta Research Council.
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