Edge herbicide approved for use with hemp

Established chemistry increases weed control options in specialty crop

Edge herbicide approved for use with hemp

Will Van Roessel may be reducing hemp acres on his southern Alberta farm this year, reflecting market signals over increasing world production, but he will be using Edge herbicide to help control pre-emergent weeds.

Van Roessel who along with family members operates Specialty Seeds near Bow Island, just west of Medicine Hat, says Edge is a valuable weed control option when producing a crop with limited crop protection options.

Bow Island, Alta., hemp producer 
Will Van Roessel of Specialty Seeds. photo: Lee Hart

“It is a very useful tool when helping to control a wide range of grassy and broadleaf weeds, particularly volunteer cereals,” says Van Roessel. As he markets hemp seed into human food markets, with hemp billed as a gluten-free product, he doesn’t want seed contaminated with any cereal grains. He says it can also be quite effective in controlling broadleaf weeds such as kochia and lamb’s quarters.

Edge granular, a long-established Group 3 herbicide has in recent years found a new fit in Western Canadian herbicide rotations. It’s an older chemistry with broad-spectrum coverage that can be quite effective in reducing the risk of developing herbicide resistant weeds. Marketed by Gowan Canada it has just recently received registration for use on industrial hemp — one of 15 crops on the product label including canola, pulse crops and several specialty crops.

Industrial hemp

Van Roessel has been growing industrial hemp for the past nine years. It is not a huge crop in Alberta, or Canada for that matter. Alberta producers grow about 25,000 acres, while statistics in recent years show Canadian production ranging between 75,000 and 100,000 acres.

Most of the production now goes into producing hemp grain used in the food market. Hemp producers are waiting for the fibre processing market to fall into place which could see new markets develop for hemp fibre used in a wide range of industrial and consumer manufacturing products such as insulated construction blocks, erosion control mats, lightweight, dent resistant car parts and even sporting equipment. Fibre processing is expected over the next few years to propel the crop from a current estimated value of about $200 million to more than $1 billion.

In the meantime, Van Roessel will be producing hemp this year both for certified seed and for the commercial food market. Producing a wide range of grains and oilseeds under an irrigated cropping system, on his farm Edge is applied and incorporated into the soil in early May just ahead of seeding.

The granular herbicide can also be effectively used in a minimum- or zero-till cropping operation, with just a light harrowing to help it make soil contact. The active ingredient in Edge, ethalfluralin, hasn’t changed but with a move toward direct seeding in dryland farming operations most weed seeds are commonly found within the top inch of the soil profile where they quickly come into contact with the surface applied herbicide.

Van Roessel says the other weed control option he has with hemp, with later emerging weeds, is Assure II. It can be used as an in-crop treatment against a wide range of grassy weeds such as foxtail barley, green foxtail, yellow foxtail, volunteer barley, volunteer corn, volunteer oats, volunteer wheat, wild oats, barnyard grass, proso millet and quackgrass.

For more information about growing industrial hemp, visit the Alberta Agriculture and Forestry website (agriculture.alberta.ca), and search for “industrial hemp.”

About the author

Field Editor

Lee Hart

Lee Hart is editor of Cattleman’s Corner based in Calgary.



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