Tighter FHB Regs, Better Management Required

“The new tolerances are designed to meet market needs but also to be fair to producers when fusarium is a grading factor in their wheat.”

– ELWIN HERMANSON

FUSARIUM DAMAGE TOLERANCES

August 1, 2010: Revise fusarium damage tolerances in CWRS, CWHWS,

CWAD, CPSR, CWSWS and CW Feed.

Wheat Class

CWRS

CWHWS

CWAD

CPSR

CPSW

CWSWS

CW Feed

Wheat, Canada Western

Grade

No. 2 CW

No. 3 CW No. 4 CW

No. 2 CW No. 3 CW

No. 4 CW

No. 5 CW

No. 1 Canada No. 2 Canada

No. 1 Canada

No. 2 Canada

No. 1 CW No. 2 CW

No. 3 CW

Feed

Current Tolerance %

1.0%

2.0% 2.0%

1.0% 2.0%

2.0%

5.0%

2.0% 2.0%

2.0%

2.0%

2.0% 2.0%

2.0%

5.0%

Recommended Tolerance %

0.8%

1.5% 1.5%

0.8% 1.5%

1.5%

4.0%

1.5% 1.5%

1.5%

1.5%

1.5% 1.5%

1.5%

4.0%

August 1, 2011: Revise fusarium damage tolerances in CWRW and CWGP.

Note: If approved by the Western Standards Committee during the 2010-11 crop year, the CWRW grade No. 3 will be established August 1, 2011.

Wheat Class Grade name

CWRW

CWGP

No. 1 CW

No. 2 CW No. 3 CW

No. 2 CW

Source: Canadian Grain Commission

Current Tolerance %

1.0%

2.0% –

5.0%

Recommended Tolerance %

0.8%

1.0% 1.5%

4.0%

Tighter tolerances for fusarium head blight damage (FHB) in spring wheat effective Aug. 1 means managing the fungus disease will be more important than ever.

The FHB tolerance for No. 1 Canada Western Red Spring wheat remains unchanged at 0.25 per cent, but the tolerance for No. 2 drops to 0.8 per cent.

The tolerances for Nos. 3 and 4 will be 1.5 per cent instead of 2.0. (See Table)

Lower FHB tolerances for Canada Western Red Winter wheat and Canada Western General Purpose wheat take effect Aug. 1, 2011.

The lower tolerances were recommended by the Western Standards Committee to better correlate the level of deoxynivalenol (DON) – the toxin created by FHB – and the percentage of damaged kernels.

“The new tolerances are designed to meet market needs but also to be fair to producers when fusarium is a grading factor in their wheat,” Elwin Hermanson, chair of the Western Standards Committee and chief commissioner of the Canadian Grain Commission said in a release.

It used to be that every per cent of visual FHB damage represented the same percentage of DON, but now it’s closer to a one to two, said Mike Grenier, an agronomist with the Canadian Wheat Board (CWB).

It will be more difficult for farmers, especially those east of Highway 34 to get a No. 2 years when FHB is high, he said.

There are several new CWRS varieties with “good” rating for FHB tolerance, including 5602, HR, Carberry and Waskada. But with most wheat already seeded, fungicides will be the next line of defence this growing season.

(Kane, Glenn and Barrie are rated “Fair” for FHB. Harvest, CGC Go and Infinity are rated “Poor.” See Seed Manitoba for a complete list of ratings.)

Farmers who want to protect their wheat from FHB this season need to follow the weather and crop development, Grenier said. The CWB’s WeatherFarm is a new, helpful tool to do that. Farmers use the Internet-based program to track Growing Degree Days in their area, which when combined with seeding date, gives growers a heads up when flowering is getting closer. Wheat flowers at 800 to 900 GGD, Grenier said.

Nothing beats field scouting so as the crop gets closer to flowering farmers should be watching their crops closely if they plan to apply a fungicide for FHB suppression, he said.

Farmers will have to decide first whether their crop is at risk or not. Warm weather with moisture or high relative humidity at flowering puts crops at risk.

“Timing is of utmost importance,” said Pam de Rocquigny provincial cereals specialist with Manitoba Agriculture Food and Rural Initiatives.

Most fungicides should be applied at the earlier flowering stage, she said. The application window for Folicur is between when 75 per cent of the wheat heads on the main stem are fully emerged (not flowering) and when 50 per cent of the wheat heads on the main stem are flowering.

Bravo 500 and Proline are also registered for FHB suppression.

Some farmers apply fungicides earlier to ward off leaf diseases and hope to get some residual FHB control, but that’s not recommended because usually it’s too soon to protect the crop from FHB.

While the timing of application is critical, so too is how well the product is applied, said de Rocquigny. Good coverage is essential. That means not travelling too fast, using lots of water and the right nozzles, she said.

Managing FHB takes planning from before the crop is planted through to post-harvest, de Rocquigny said. Crop rotation can help.

Bayer CropScience’s Proline provides longer protection than its other FHB fungicide Folicur. But Proline is more commonly used in canola for sclerotinia control because it’s more expensive than other wheat fungicides.

However, Graham Hastie, manager of Bayer’s cereal crops fungicides/insecticide and seed treatment says there are program discounts that make Proline more affordable.

Meanwhile, both Bayer and BASF were hoping to introduce two new FHB cereal fungicides this year – Prosaro and Caramba, respectively, but the Pest Management Regulatory Agency has yet to register them.

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About the author

Reporter

Allan Dawson

Allan Dawson is a reporter with the Manitoba Co-operator based near Miami, Man. Covering agriculture since 1980, Dawson has spent most of his career with the Co-operator except for several years with Farmers’ Independent Weekly and before that a Morden-Winkler area radio station.

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