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Volume 39, Number 9 | APRIL 1, 2013

$4.25

PRACTICAL PRODUCTION TIPS FOR THE PRAIRIE FARMER

www.grainews.ca

The future of weed control While high costs are still a hurdle to overcome, bioherbicides are in the works and could be a weapon in the struggle against herbicide resistance BY LISA GUENTHER

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esearchers in Canada and the United States are developing bioherbicides that will not only give organic and conventional farmers more weed control options, but also, in some cases, control herbicide-resistant weeds. Bioherbicides are synthetically produced compounds identical to chemicals found in nature. They may be sourced from micro-organisms or plants. Bioherbicides can also include whole microorganisms that infect weeds. Currently there are no bioherbicides registered for use on agricultural crops in Canada, but researchers with Agriculture and Agri-Food Canada (AAFC) are working to change that.

FUNGAL BIOHERBICIDES Phoma is a fungal bioherbicide that controls Canada thistle, dandelion and wild mustard. The Pest Management Regulatory Agency (PMRA) approved Phoma for turfgrass in 2011, and it will be commercially launched in 2014. Dr. Karen Bailey is an AAFC researcher based in Saskatoon. Bailey and her colleagues are studying the use of Phoma in agricultural crops. Bailey plans to study Phoma’s efficacy in wheat and barley this year. She already has two years of data on alfalfa, funded by the alfalfa seed commissions in Saskatchewan and Alberta. Wide row spacing leaves alfalfa crops vulnerable to weeds before the crop is established. So far Bailey’s results are positive, though she has found that using Phoma the year the alfalfa is seeded harms the crop. “And the interesting part that we found actually with the alfalfa was that even though it harmed the crop in the first year, by the time it had its next year, the crop had recovered so that there were no differences among our treat-

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PHOTO: MARRONE BIO INNOVATIONS

Marrone Bio Innovations’ bioherbicide, Opportune, controls broadleaf weeds in grasses. It has been submitted for approval in Canada. ments relative to an untreated control,” says Bailey. Applying Phoma in the years after the alfalfa is seeded doesn’t harm the crop. Bailey says organic farmers are very interested in using Phoma to control weeds such as Canada thistle. She thinks some conventional farmers may use it as well. “I think it’s going to be probably (a fit with) some people’s philosophies, as long as the product works. And I think some people will find it as an alternative to be able to use in some situations. In other cases it may just be a novel way of control for them.” Whether Phoma proves useful for treating herbicide-resistant weeds depends on which weeds it’s approved to treat, Bailey says. “But we do know bioherbicides do provide different mechanisms of action.” Bailey’s colleague, Dr. Susan

Boyetchko, is studying bacteria that control wild oats and foxtail. Boyetchko’s work shows that bacteria control herbicide-resistant weeds.

BIOHERBICIDES IN THE U.S. There aren’t many bioherbicides on the market in the United States right now, either, and many are aimed at the organic market. Marrone Bio Innovations is a California company that develops biopesticides. The company’s bioherbicide, Opportune, has been approved by the U.S. Environmental Protection Agency (EPA). Marrone Bio Innovations has also submitted Opportune to the PMRA for approval in Canada. “Historically bioherbicides have not broken through and (have had) very small sales because somebody would look for a microbe that

would infect and kill a weed,” says Dr. Pam Marrone, CEO of Marrone Bio Innovations. Part of the reason previous efforts have had limited success is that the microbes being used only worked on a few specific weeds. Bioherbicides that control more weeds have more potential for conventional agriculture, especially with growing herbicide resistance. The active ingredient in Opportune is a microbial compound, rather than the entire microbe. “There’s no infection process of the weed. It’s strictly based on the microbe producing a compound. The compound kills the weed,” says Marronne. The compound is selective, so it won’t kill grasses such as corn, wheat, rye and turf. Marrone says it controls broadleaf weeds in grasses

In This Issue

post-emergence, and can be used in any crop before planting. Marrone Bio Innovations also has two bioherbicides on deck. One, which has been submitted to the EPA, uses a compound from a Chinese pepper plant, and can be used as a post-emergent burndown for grasses and broadleaves. The other bioherbicide uses several compounds from a bacterium.

LOWERING COSTS A PRIORITY “The problem with (chemical) herbicides is that they’re so lowpriced that it’s hard to find bioherbicide technology that can get you down to the price to compete,” says Marrone. When researchers and companies first find a bacterium, plant, fungus, or other organism that pro-

» CONTINUED ON PAGE 4

Wheat & Chaff ..................

2

Features ............................

5

Crop Advisor’s Casebook

18

Columns ........................... 27 Machinery & Shop ............ 34 Cattleman’s Corner .......... 40

First time with fababeans SARAH WEIGUM PAGE 8

Farmer panel

LEE HART PAGE 22

FarmLife ............................ 45


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