The Pre-emergent Weed Control Advantage

Growers should consider “herbicide layering” as a strategy to help manage herbicide resistance. This practice involves using a pre-emergent herbicide prior to an in-crop herbicide application. This program allows for multiple modes of action to be utilized. In addition, pre-emergent weed control gets the crop off to a fast, clean start to help maximize yield potential.

Avadex MicroActiv, Fortress MicroActiv and Edge MicroActiv pre-emergent herbicides add 6 to 8 weeks of residual control, giving control of flushing weeds and a layer of protection in case post-emergent herbicide application gets delayed. Control of any escapes is also made easier.

Avadex MicroActiv is a Group 8 granular pre-emergent herbicide that can be used for spring wheat, barley, canary seed, flax, canola and peas. The product controls wild oats including Group 1 and Group 2 resistant biotypes. Other benefits include reduction in early-season weed pressure and more flexibility with timing post-emergent herbicide application. Avadex MicroActiv can be applied in fall after Oct. 1 when soil temperature at a depth of two inches is 4°C or less and within 3 weeks of soil freeze-up. A single heavy harrow pass is sufficient incorporation in minimum or zero-till fields. Avadex MicroActiv can be used in conventional tillage, but should be applied after fall tillage then incorporated with a single harrow pass. Do not apply in fall on minimum tillage fields with less than 2% organic matter. Spring rate is 10 to 15 lbs/ac for wheat, 12.5 to 15 lbs/ac for barley and canary seed, and 15 to 20 lbs/ac for flax, canola and peas.

Avadex Liquid EC is available for growers using a conventional tillage system. The product controls wild oats (including Group 1 and Group 2 resistant biotypes) in the same registered crops as Avadex® MicroActiv. Fields need to have 60 to 70% of the soil showing. A light incorporation is required. Another option is to tank mix with a pre-seed herbicide which adds residual control of wild oats to the burndown, delay incorporation for at least 24 hours. Spring rate is 1.0 to 1.4 litres/ac.

Fortress MicroActiv is a Group 3 and Group 8 granular pre-emergent herbicide that can be used for spring wheat, barley, canola and flax. The product provides control of wild oats, green and yellow foxtail, as well as suppression of kochia, redroot pigweed, wild buckwheat, lamb’s quarters, and Russian thistle. Fortress MicroActiv can be applied in fall after Oct. 1 when soil temperature at a depth of two inches is 4°C or less and within 3 weeks of soil freeze-up. A single heavy harrow pass is sufficient incorporation in minimum or zero-till fields. Fortress MicroActiv can be used in conventional tillage, but should be applied after fall tillage then incorporated with a single harrow pass. Do not apply for wheat in soils with 2% or less organic matter in fall. Spring rate for wheat is 10 lbs/ac (wheat must be in soils with greater than 4% organic matter), for barley it is 10 to 12.5 lbs/ac depending on organic matter. Spring rate for canola and flax is 12.5 to 15 lbs/ac.

Edge MicroActiv, a Group 3 pre-emergent herbicide can be used for soybeans, canola, peas, dry beans, sunflowers, alfalfa (establishment) and hemp. The product will provide early weed removal and residual control of grassy and broadleaf weeds. Edge MicroActiv will control kochia, wild buckwheat, redroot pigweed, lamb’s quarters, cow cockle, chickweed, purslane, corn spurry, barnyard grass, as well as green and yellow foxtails. Weeds suppressed include wild oats, cleavers, hemp-nettle, lady’s-thumb, Russian thistle, and volunteer wheat and barley. Edge MicroActiv can be applied in fall after Oct. 1 when soil temperature at a depth of two inches is 4°C or less and within 3 weeks of soil freeze-up. For zero or minimum-till, a surface application and light harrowing will provide optimum control. Spring rate is 7.5 to 12.5 lbs/ac.

For conventional tillage Edge MicroActiv can be applied starting on September 15th. Edge MicroActiv should be applied before the tillage operation and be worked in with a disc or cultivator to your normal working depth. A second incorporation should be done on a right angle either a minimum of 3 days later or the following spring to ensure even distribution through the top of the soil. For a spring application with conventional tillage, Edge MicroActiv requires a more thorough incorporation (consult your Shur-Gro agronomist).

Tips for successful application of Avadex MicroActiv, Fortress MicroActiv and Edge MicroActiv:
1) Product rates are determined by % organic matter of the soil. Consult product labels.
2) Complete any field cultivation. Harrow heavy trash or large clods before application.
3) Apply using a floater or Valmar and incorporate using a heavy harrow.
4) With min-till, one harrow pass is usually sufficient incorporation.
5) For a spring application, apply and incorporate 7 to 10 days ahead of planting. This will allow time for the herbicide to activate.
6) Apply pre-seed glyphosate to address early weeds that emerge before herbicide activation (if necessary). Plant the crop, followed by post-emergent control.