Alberta Weed Survey: 2009-2010

Irrigated and Dryland Fields

Agriculture and Agriculture et Agri-Food Canada Agroalimentaire Canada

Julia Leeson & Chris Neeser

Content

• Overall weed abundance • Trends • Distribution maps • Results from weed management

questionnaire

Background

• 1st Weed Survey 1930-1931 • Series of partial surveys 60’s and 70’s • Intensive survey Fort Vermillion in 1985

(model for future surveys) • 1st Province-wide survey 1997 (684

fields) • 2001 survey 1153 fields surveyed

What we did in 2009

• Irrigated Fields (12 districts) • Surveyed 571 fields out 600 target • Distributed 600 questionnaires, 239

were returned (38%)

What we did in 2010

• Surveyed 959 dryland fields (target 1200)

• Covering 88 ecodistricts • Mailed out 950 questionnaires, of which

235 were returned (25%)

Weed Survey Protocol

100 paces

100

pace

s 5

1 10

15

20

20 paces between samples

Field corner or other convenient

starting point

Data Analysis Relative Abundance = Relative Frequency + Relative Uniformity + Relative Density

countweedTotalspeciesweedbyCount

FrequencyRelative =

quadrats ofnumber Totalspeciesweedgiven a with quadrats ofCount

UniformityRelative =

countweedTotalspeciesweedgiven a ofCount

DensityRelative =

Irrigation Districts

Irrigation District:WesternEastern Bow River Lethbridge Northern St. Mary River Taber Raymond MagrathUnitedMountain View Leavitt Aetna Ross Creek

Calgary

Brooks

Medicine Hat

Lethbridge

Glenwood

Irrigation District:WesternEastern Bow River Lethbridge Northern St. Mary River Taber Raymond MagrathUnitedMountain View Leavitt Aetna Ross Creek

Calgary

Brooks

Medicine Hat

Lethbridge

Glenwood

Top 20 Species in Irrigated Broad-leaved crops (beans, potatoes, sugar beets, canola)

Top 20 Species in Irrigated Annual Cereal Crops (includes corn)

Top 20 Species in Irrigated Perennial Crops (alfalfa, grass hay)

Total Weed Density by Crop

Top 20 Species in All Dryland Crops (2010)

Top 20 Species in Dryland Cereal Crops (2010)

Top 20 Species in Dryland Peas and Canola (2010)

Top 20 Species in Perennial Crops (2010)

Since the 70’s

Since the 70’s

Since the 70’s

Since the 70’s

Maps

Wild Buckwheat

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Wild Oat

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Dandelion

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Canada Thistle

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Cleavers

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Annual Sow Thistle

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Narrow-leaved Hawk’s-beard

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Kochia

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001 2010

Canada Fleabane (Conyza canadensis)

Not included

absent

0.1 to 1

1.1 to 4

4.1 to 10

> 10

Legend (Relative Abundance)

2001

The Questionnaire

• 33 questions specific to the surveyed field • weed management • insect and disease management • tillage, seeding, soil fertility, yield and rotations

• 18 questions about the farm operation • Overall weed management • herbicide resistance • Sprayer calibration

Herbicide Use: % untreated

Herbicide Use: Barley

* includes all Monsanto glyphosate products

Herbicide Use: Wheat

Herbicide Use: Canola

Herbicide Groups: 2010 Barley (56 fields)

Herbicide Groups: 2010 Wheat (92 fields)

Herbicide Groups: 2010 Canola(61 fields)

Crop Rotations (2007-2010)

Herbicide Resistance

Suspected species Nb of fields Herbicide Groups

Wild Oats 34 1, 2,

Kochia 12 2, 4

Wild buckwheat 4 2

Chickweed 2 2, 4

Cleavers 1 2

17 % of respondents suspected herbicide resistance.

Herbicide Resistance

Confirmed species Nb of fields Herbicide Groups

Wild Oats 11 1, 2,

Kochia 4 2

Chickweed 2 2

Hemp-nettle 1 2

5 % of respondents had confirmed herbicide resistance.

Key Conclusions • Generally good weed control in high value

cash crops (potatoes, beans, sugar beets, canola).

• Weed control is better than in the 70’s and 80’s

• Annual sow thistle, narrow-leaved hawk’s-beard, and Canada fleabane continue to spread

• Herbicide resistance is a significant problem in spite of herbicide rotations

Acknowledgements • Julia Leeson and students at AAFC in Saskatoon • Nicole Kimmel and Cindy Samborsky from the Pest

Surveillance Branch • Maureen Vadnais from Ag Service Board • Agricultural fieldmen • Agricultural Research and Extension Council of

Alberta (BRRG, CARA & SARA) • Number of Crop Consultants • Participating Farmers

Chris Neeser 403 362-1331 chris.neeser@gov.ab.ca

Julia Leeson 306-956-7270 julia.leeson@agr.gc.ca

Agriculture and Agriculture et Agri-Food Canada Agroalimentaire Canada

Herbicide Timing

Number of Herbicide Applications

Ratings of Weed Management Practices

Sources of Weed Management Advice

Objectives • To quantify weed populations in terms of

their diversity and density of the principal annual crops grown in Alberta, either with or without irrigation.

• To document the agronomic and weed control practices used on surveyed fields

• To examine correlations between weed management practices and weed populations.