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Stay ahead of weeds with fall applications

It’s hard to believe harvest season is nearly over and timing for fall herbicide application is now front and center. I was hoping the supply chain issues we faced earlier this year would be resolved and product orders and anticipated arrival dates would have reverted to “normal,” although who knows what the definition of “normal” is anymore? Unfortunately, several indicators have signaled to us that acquiring products in 2022 may be equally or more difficult than what we expe­rienced in 2021. That’s why I want to emphasize the importance of having a couple of crop protection plans in place. Products you used in the past may either price you out of the market or require you to call an audible before spraying due to tight or empty inventory.

Successful audibles in the game of football, called at the line of scrimmage, have been planned and rehearsed with all players focused on the routes ahead and which op­ponents to block. The outcome of a well-planned and rehearsed audible called in the field is often no dif­ferent at the farm level. I say “often no different” because we all know how unforgiving and unpredictable Mother Nature and government decisions can be at times.

So what can we expect for 2021 fall herbicide supply? We know products that contain glyphosate and 2,4-D will be in tighter supply. It’s fair to encourage folks to order what they need for this growing season and not what they may need for the next two or three years. No one wants a repeat of the toilet paper debacle we faced during the beginning of the pandemic in 2020.

Herbicide applications in the fall are a great way to stay ahead of the game and control winter annual weeds that emerge during and after harvest. A couple things to keep in mind when deciding on fall chem­ical products. Historically, glypho­sate and 2,4-D have been econom­ical and effective options for many difficult-to-control winter annual weed species. These products have been applied across a large portion of acres in our trade territory in the past. If you have access to glypho­sate and 2,4-D, I would direct use of this mixture towards fields with heavy weed populations first. Most growers know which fields on their farm are typically weedier than others. Start there.

Aside from glyphosate and 2,4-D, there are other fall herbicide options to consider in fields where corn will be planted the following year. Many of these products have residual activity where glyphosate does not and 2,4-D is limited. These fall herbicides include Basis/ Resolve Q, Resolve SG and Princep.

In fields where soybeans will be planted the following spring, several herbicides that contain Authority can be applied in the fall. Other products such as Canopy/ Canopy EX, Classic, Envive, Fierce XLT, Pursuit, Sharpen and Synchro­ny XP are also labeled in the fall for spring-planted soybeans.

Some of the previously listed herbicides are, or have, active ingre­dients that inhibit acetolactate syn­thase (ALS) and can persist longer in soils where the pH is greater than 7. Be cautious of the maximum annual use rate on ALS chemistries in the spring if you have fields with pH values in the mid to upper 7s.

If you are unsure if you will be planting corn or soybeans next spring, there are still many op­tions that can be applied in the fall. Anthem Flex, Authority MTZ, Autumn Super, Elevore, Express, Fierce MTZ, Gramoxone, Harmony, Kyber, Quelex, Volunteer, Metribuz­in and Valor EZ can be used in the fall where either corn or soybeans will be planted the following spring. Some products may need to be tank-mixed for optimal weed control. Most of these products, if they have much grass activity, will need to be applied to weeds smaller than the 4- to 8-inch-tall grasses we have controlled with glyphosate in the past.

Generally speaking, fields with heavy winter weed pressure are better candidates for fall herbicide applications than fields with low weed pressure. Adding residual herbicides in the fall generally translates into a cleaner seedbed but should not replace a spring residual application. By springtime, the concentration of herbicide in the soil solution will unlikely be at concentrations lethal to prob­lematic emerging species such as waterhemp, Palmer amaranth and horseweed.

With all the uncertainty in the crop protection market, I cannot stress enough the importance of having a cropping plan for the 2021-2022 season. I can assure you MFA’s crop protection team is diligently working to meet the needs of our customers, and our agronomy team is equipped and ready to service our locations and member-owners as crop protection needs continue to evolve.

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