Weed of the Week: foxtail barley

Foxtail barley has become a perennial problem in minimum tillage fields across Western Canada.

But how did it get this way? The plant is a poor competitor and can be killed with a variety of herbicides.

Tillage is the most effective control, but most producers no longer use it.

Hordeum jubatum thrives where there has been too much water and where salinity is high. It also does well in areas where it is left alone, or in fields where cereals are a major part of the rotation.

The effects of several years of flooding and saturated soils that prevented cropping and weed control in large areas of Western Canada have contributed greatly to the pest’s rise.

Seeds can germinate and create viable seedlings in any part of the growing season and are wind carried and capable of surviving in the soil for up to seven years.

Patch control is encouraged be-cause foxtail barley can be controlled with aggressive steps with little loss of crop.

Heavy, aggressive cropping, combined with herbicides can weed out this weed.

Herbicide tolerant cropping, where dense crop canopies such as gly-phosate or other herbicide tolerant canola can be established, along with a pair of pesticide applications that can take place in-crop, can be effective against foxtail barley, which is also know as wild barley.

Late fall applications of herbicides provide better control of established foxtail barley plants than spring applications.

Suppression is usually the best that can be expected in foxtail barley infestations for in-season applications of most herbicides.

The use of combination products like Rustler, glyphosate and dicamba, at 1.26 litres per acre are also effective before the initiation of the seed head or when bottom leaves begin to brown off.

Glyphosate and Express SG, tribenuron, are also used for suppression of this stubborn cereal.

In broadleaf crops Post Ultra, sethoxydim, at .45 litre per acre provides suppression before tillering of the weed. Assure 2 and Yuma, quizalofop, can also be effective for post emergent use. Everest can be effective in controlling multiple flushes of the pest’s seedlings.

Dicamba, Banvel or Oracle, and 2,4-D at the highest rates might provide control in grass pasture and other conditions. Dyvel DSP is a combination product, but the weed is not on that label.

Gramoxone, paraquat, at a rate of 2.23 litres per acre in 98 gallons per acre of water, 75 millilitres with 2.2 gallons will kill top growth and likely any seedlings.

Adding granular ammonium sulfate to a glyphosate application at three kilograms of 21:00:24 per 100 litres, can improve the effectiveness of the herbicide, especially in tough growing conditions or in the fall. Premixing the fertilizer into solution is required.

In established alfalfa seed crops and grass and legume pastures, the use of Kerb 50 W, propyzamide, can be used later in the fall or in early spring.

There is a 60 day grazing and haying restriction.

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