Four Ways To Use The Herbicide Wall Chart

Grainews and Dow Agro-Sciences have joined forces to provide you with a comprehensive wall chart to assist in making herbicide selections this year. This easy-to-use chart is included in this issue of Grainews. Simply unfold the chart, hang it in the office, or chemical shed or the place where you make herbicide selection decisions. It will be a quick and handy reference when deciding which herbicides are the best fit for your crop rotation and the weed spectrum in your fields.

The Grainews/Dow AgroSciences chart simplifies and condenses information from the provincial crop protection guides so you can quickly and easily narrow herbicide selection to one or two “best” choice products. From there, you can look up more thorough descriptions and instructions in the provincial crop protection guide. Because the chart is based on the guides, any product introduced after its publication is not included on this year’s chart.

The tables are not intended to be a substitute to reading the herbicide label, either. The wall chart is merely a selection guide; you must still refer to the label to determine specific crops, crop staging, rates and a host of other factors that are critical to good weed control and crop safety.

The wall chart is designed to assist you in determining which herbicides are a good fit for the crops, weed spectrum and herbicide rotation. The use of the wall chart should save you time, money and reduce the frustration of trying to find the “right” herbicides to use.


For most farm managers, selection of the best herbicides to use has become the toughest part of weed management. Farmers are faced with a growing list of herbicide names, yet many “new” herbicides are simply rebranding of existing products and active ingredients. Multiple brands of the same chemistry complicate herbicide selection. Different brand names of the same active ingredient can be confusing as farmers seek different products to insure they are rotating herbicide groups. Instead of a long list of all the herbicide brands on the market, the Grainews/Dow AgroSciences wall chart lists the original brands first, with the licensed and off patent brands next (except in the glyphosate table). This allows farmers to compare different chemistries rather than brand names when selecting herbicides. And it quickly shows you which brand names are clones of other products.

Since an increasing number of weeds are developing resistance to herbicides, rotation of herbicide groups is extremely important. The Grainews/Dow AgroSciences wall chart addresses this important consideration by assigning the first column and first row of the tables to the chemical group number of every grassy and broadleaf herbicide.

By prominently displaying the product groups as the tables do, farmers can easily predetermine which herbicides are from different groups than the herbicide group which was applied to the field the previous year. This allows you to narrow your herbicide selection choices.


Tank mixing two or more products from different groups is a recommended method for reducing the risk of weeds developing herbicide resistance. The Grainews/Dow AgroSciences wall chart identifies which grassy and broadleaf products are registered for tank mixing.

Pre-formulated mixtures of two broadleaf active ingredients are included in the chart under a combined grouping. For example, Buctril M is a pre-formulation of MCPA (Group 4) and bromoxynil (Group 6) therefore it is listed under the broadleaf Group 4+6.

The chart also lists supplementary tank mixes that may be possible between broadleaf products.


Still, the most important factor in making a good herbicide selection is to match the weeds in your field with the weeds on the herbicide label. The Grainews/Dow AgroSciences chart lists the most important western Canadian grassy and broadleaf weeds and shows the degree of control a grower can expect on a specific weed from each herbicide. A farmer who does a good job of scouting will be able to compare his list of weeds in the field with the control ratings for each product to find the best match of herbicides for the specific weed spectrum in the field.


Another feature of the wall chart is that information is provided not only for weed control in cereals, but also separate tables are provided on the chart for pulse crop weed control, oilseed crop weed control, and even a fourth table detailing the numerous glyphosate brands and their active ingredient concentrations. The Grainews/Dow AgroSciences chart is a one stop herbicide selector for all major western Canadian crops.

Gerald Pilger farms at Ohaton, Alta., and worked day and night putting this chart together. Do him a favour and use it.

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