Canola Facts

• Bright yellow-flowering member of the Brassicaceae (mustard) family.

• Cultivated for animal feed, vegetable oil for human consumption and bio diesel.

• Third leading source of vegetable oil in 2000

• World's second leading source of protein meal.

Common Weeds of Canola

Weed Problems

• Cause competition

• Can reduce yield and oil content

• Contaminant seed

• Decrease in plant vigor

• Wild radish or wild turnip seeds could be a serious problem

Crop Yield Loss Due to Weeds

• Vary with the weed species and density of the weed as well as timing of weed emergence

• Later-emerging plants tend to be less competitive and produce fewer seeds per plant

• Canola, once established, is more competitive with weeds than row crops such as corn or soybeans

Weed Prevention and Control

• Plan early

• Use crop rotation

• Row width

• Plant population

• Variety characteristics

• Tillage practices

Weed Control• Young seedlings are very sensitive to early weed

competition.• An effective weed control program should include cultural,

mechanical and chemical methods• Once established, canola is a good competitor with most

weeds• Follow cultural practices to assure a dense, vigorous

developing crop that will compete well with weeds• Pay attention to seeding dates, rates, and depth of seed

placement• Perennial weeds should be controlled the year prior to

seeding • Few herbicides labeled • Canola is extremely sensitive to drift from broadleaf

herbicides

Common Weeds

• Field scouting is important as weeds vary from field to field and each field must be carefully assessed before planting it to canola.  Identification, recognition and detection of weeds are important to crop management.  The most prevalent weeds based on provincial weed survey’s are…

Common Weeds

• Wild oats  • Wild buckwheat  • Lamb's-quarters  • Redroot pigweed  • Lady's thumb  • Russian thistle  • Hemp nettle  • Cow cockle  • Field horsetail  • Shepherd's-purse  • Chickweed• Wild rose

• Green foxtail  • Stinkweed  • Canada thistle  • Green smartweed  • Sow thistle  • Wild mustard  • Bluebur  • Night-flowering catchfly  • Barnyard grass  • Flixweed  • Volunteer canola

Problem Weeds in Canola

• Perennials

• Shade- tolerant

• Tall-growing

• Early-germinating weeds such as wild oats

  

Problem Weeds in Canola

Troublesome weeds not controlled in a conventional canola crop with lower cost herbicides:

• Wild mustard  • Stinkweed  • Shepherd's-purse  • Ball mustard  • Flixweed  • Wormseed mustard  • Hare's ear mustard  • Common

peppergrass

Problem Weeds in Canola

• Easily controlled in cereal crops and herbicide-tolerant canola

• Dormant seeds and seeds from escapes will germinate and set many more seeds in conventional canola

• Results in a gradual build-up of weed populations when canola becomes more frequent in the rotation  

• Stinkweed seeds can remain viable and dormant in the soil for 10 to 20 years

• Wild mustard seeds can remain dormant for more than 30 years

Notice that most of the common weeds that affect Canola look very similar to Canola itself. Many are in the same family. They produce seeds like Canola would and this is why they are a problem. The seeds get mixed in with the crop during harvest and contaminates it. It is very important to be able to identify the many different weeds so you know what you are dealing with. From a distance many of these weeds can be mistaken for Canola.

Wild Mustard

• One of the most serious canola weeds

• Yield loss

• Serious contaminant of canola seed

• If more than 5% wild mustard is present in a canola sample, graded "sample reject"

Wild Mustard Biology

• Branched stem is erect, • About 3 feet tall• Short, stiff hairs, especially on the lower part of the stem• Leaves are alternate and coarsely- toothed• Similar to canola, the flowers are bright yellow• Mature wild mustard has purple color on stem • Produces 2,000-3,500 seeds per plant• The seeds are brown to black • Early, dry conditions keep populations of wild mustard

low.

Scouting Wild Mustard

• Take a minimum of 20 weed counts across field

• Wild mustard seedlings look very similar to Polish canola

• Take plants confirmed to be Polish canola and wild mustard and compare them for subtle differences

• Look between rows when trying to identify wild mustard in Polish canola

Wild Mustards Effect on Crop

• Wild mustard seed is similar in size and shape to canola seed

• Impossible to separate by conventional methods

• Densities as low as 20 plants per square yard in canola may result in wild mustard accounting for up to 5% of the harvested seed, the maximum tolerance of wild mustard in any grade of canola.

Wild Mustard Control Tips

• Flourishes under cool, moist conditions

• Pay attention to weed staging under these conditions

• It grows quickly and can escape the window for herbicide application

• Herbicide options are available in most crops

Stinkweed

Shepherd's-purse

Ball mustard 

Flixweed 

Wormseed mustard

Hare's ear mustard

Common peppergrass

Wild Oats in Canola

Common Lambsquaters in Canola

Works Cited

• www.gov.mb.ca/agriculture/crops/weeds/images• http://www.ext.nodak.edu/extpubs/plantsci/crops

/a686w.htm• http://www.industry.gov.au/biotechnologyonline/f

oodag/weeds.cfm• http://agspsrv34.agric.wa.gov.au/agency/pubns/f

armnote/1997/f02197.htm• http://www.canola-council.org/weedproblem.asp

x• http://www.gov.on.ca/OMAFRA/english/crops/pu

b811/8weed.htm