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Kitchen condiment tackles weeds with flavour

A sprinkling of vinegar replaces pesticides An unexplained craving for fish and chips while strolling through the village can be traced back to a few backpacks filled to the brim with pickled vinegar.
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A sprinkling of vinegar replaces pesticides

An unexplained craving for fish and chips while strolling through the village can be traced back to a few backpacks filled to the brim with pickled vinegar.

While most people carry lunch or a change of clothes in their packs, municipal work crews have been strapping on clear packs full of vinegar, complete with a nozzle and spray hose.

Their mission: to attack the unsightly weeds poking through the paving stones throughout the village.

The vinegar is killing weeds dead like any good pesticide, without the harsh environmental ramifications of spraying chemicals.

"So far it’s proven to be pretty effective," said Paul Beswetherick, the municipality’s landscape supervisor.

"It’s certainly better than using most of the registered pesticides."

While registered pesticides are required to list the active ingredients in their make up, there is no law insisting on a list of the carriers in the pesticide.

Some of these carriers, which act as a spreading agent or a bulking agent, are a cause for concern, said Beswetherick.

Past studies have linked some pesticides to different types of cancer in humans, from breast cancer to non-Hodgkins lymphomas.

Pesticide use is also linked to toxicity in watercourses, which in turn harms fish and wildlife.

The municipality has been exploring the use of vinegar for about two years as it strives for a pesticide-free operation.

Beswetherick said the vinegar backpacks are still in the experimental stages.

"We are expanding our testing but it still is in a testing phase," he said.

"We’re assessing what’s going on and keeping a close watch on it."

While vinegar may be an effective short-term solution, there are concerns that it may not sustain its capabilities over the long-term, he said.

"We have to maintain the quality of the product at the same time... We’re really making sure that we’re on firm ground before launching into the abyss."

The municipality’s experiment is running in conjunction with an American study in Maryland by the Agricultural Research Service.

Agronomist Dr. Jay Radhakrishnan has been working on the vinegar experiment for almost two years and is very happy with the results to date.

"I think the implications are tremendous," he said.

"It’s great for the environment and it’s also good for the organic farmers."

The U.S. research team has found that spraying a five per cent concentration of vinegar, the equivalent of household vinegar, can have a 100 per cent kill rate of certain weeds like Canada thistle.

"If you catch them young, you get 100 per cent (kill rates)," he said.

Vinegar is most effective during the first two weeks of the weed’s life.

Some older plants need higher concentrations of vinegar to be effective and the researchers use up to 20 to 30 per cent concentrations in those cases.

Along with Canada thistle, vinegar tests are being done on weeds like common lamb’s quarters, giant foxtail, velvetleaf and smooth pigweed.

The positive results in the U.S. are similar to the results in Whistler.

Here the vinegar is only being sprayed on the weeds, like annual blue grass, which grow between the paving stones in the village.

"It’s effective on any newly sprouted weeds," said Beswetherick.

"It doesn’t matter what kind they are as long as they don’t grab a foothold."

Municipal work crews have not used registered pesticides in any form since 2000 – and haven’t used any in municipal parks for more than a decade. The vinegar is just one in a series of tools that they use to stay on a pesticide-free path.

Work crews have also experimented with a steam weeder, called an Aquacide.

"Basically it just cooks the plants on contact," said Beswetherick.

"It’s very effective but it does require repeat applications and it’s a cumbersome machine."

And they have also used infra red weeders which are propane powered. The propane heats up a ceramic heater pad over the pavers and it cooks the weeds.

"We are hopeful that the vinegar application will be more effective for us," he said.

Outside of the paving stones in the village, municipal work crews do all the other weeding by hand.

"We don’t spray anything anywhere else," Beswetherick said.

"We do hand work and we plant material that will cover the ground in such a way that it out-competes the weeds."

Beswetherick said a lot of weed management starts with TLC of the soil.

"If you don’t have soil in prime condition, well-watered and full of nutrients, you’re going to have trouble.

"We’ve raised our tolerance. We find that so long as we can keep our horticultural conditions at their prime then the plants are able to resist pests much better."

He has looked into using vinegar on weeds other than those growing within the pavers but for anything that has a strong root system, the vinegar is not as effective – the stronger the root system, the more repeat applications of vinegar, at a higher concentration, are needed.

Still, its success so far has prompted more research at the Agricultural Research Service.

Radhakrishnan said the potential applications for vinegar as a weed controller range from the average homeowner controlling growth in their yards and patios to municipalities controlling vegetation along roadsides.

It is also an inexpensive and environmentally safe spot treatment on organic farms.

Currently the vinegar applications cannot be used as a gentle broadcast spray on farms, as scientists are still researching the effects of vinegar on various crops.

In addition Radhakrishnan said the vinegar is not sticking to some of the waxy leaf plants when sprayed on a broad basis.

"It won’t replace all the chemical use... but it will be an alternative that can be used," he said.

And the studies are still ongoing, he added.

Since the news was released in May that researchers were testing vinegar scientifically, Radhakrishnan said he has been flooded with phone calls and e-mails about personal successes and failures with vinegar.

He said the scientists are working on interesting studies on the use of vinegar in the soil with some very good results, but he was not able to reveal any further information.

Still, Beswetherick is cautious of moving entirely to vinegar applications as a replacement for all pesticides.

"I wouldn’t go as far as to say we’re pesticide free but we are chemical free," he said.

He keeps products on hand, like Safer Soap for knocking down aphids, if there is a problem.

Safer Soap is a natural mineral oil and a registered pesticide.

Beswetherick says each experiment, from vinegar sprays to infra red weeders, is a step in the right direction.

"Everybody is really aware in the valley about how the application of chemicals is detrimental to the environment," he said,

"It is a gradual process."