Rotation stays ahead of possible resistance problems

Justin Dagen

Weed control is not a new problem. Many of us are familiar with the early evidence, as written in Genesis 3:17-18 as the Lord spoke to Adam: “Cursed is the ground for your sake; in toil you shall eat of it all the days of your life. Both thorns and thistles it shall bring forth for you.”

WEED-CONTROL RECIPE: Using a combination of advice from agronomists, chemicals and crop rotation is the best way to battle weeds in your fields.

Having been raised in an area of numerous rotation crops, my early recollections of weed control were quite simple. The potato grower used a Lilliston rolling cultivator. The sugarbeet grower used Christmas chemical (hoe, hoe, hoe). The wheat grower used a few ounces of 2,4-D to control the occasional wild mustard. Any corn that was grown was chopped and fed to cows; soybeans had not been adapted this close to the Arctic Circle. In addition, all the land was moldboard-plowed every year.

Fast-forward 50 years and conservation compliance regulations — not a bad thing — caused the vast majority of moldboard plows to be melted down and reborn as various conservation tillage tools. Now, zillions of weeds sit at or near the soil surface, as opposed to the moldboard plow days when the seeds were buried 8 inches deep where the sun doesn’t shine.

Tillage methods however, are only one piece of the weed-control puzzle. The introduction of glyphosate in the 1970s and glyphosate-resistant crops in the 1990s is clearly the elephant in the room. Weed control became easy, simple and painless — and many producers became complacent.

Our farm is blessed to be located in an area where it is not uncommon to cash-flow 10 or 15 different crops in a given year. We normally grow at least six crops every year on our farm, meaning weeds will face a dozen or more different herbicide compounds in the six-year cycle.

Rotation is our trump card when it comes to beating resistant weeds (no politics involved). Mr. Palmer will get a harsh reception if he tries to set foot on our farm.

Scout and keep those weeds from going to seed

Rochelle Krusemark

Palmer amaranth was recently identified in southwestern Minnesota, so early weed detection and aggressive management are essential.

Waterhemp and pigweed are the current "thorns in our side." Weed management at Krusemark Farms will continue to follow best management practices to manage resistant and tough-to-control weeds. The goal is zero tolerance — which is not necessarily a weed-free field, but to keep resistant weed biotypes from going to seed.

Working with our agronomist, Jeff Crissinger at NuWay, we determine which herbicide traits will be effective to address issues for each field. Scouting fields is imperative. You cannot develop a plan without identifying the target! Tentative plans for 2017 include a preemergence herbicide to keep fields clean in the early season, when young plants thrive without competition for sun and nutrients. Our 22-inch rows tend to canopy early, which suppresses weed growth between rows. We will follow up with postemergence treatment, and control weed escapes by spot spraying. We realize weed control includes ditches, tree lines and fencerows, so we use the UTV with a boom-less nozzle and hand-wand to control these areas.

Let’s all practice stewardship by applying herbicides correctly, including full usage rates, appropriate spray volume and nozzle selection. Adopting an integrated weed management program, deploying multiple effective modes of action, having herbicide diversity and using crop and trait rotation have been effective on our farm, and we hope those practices work for you, too. Farmers are independent businesses, yet we are partners. Thanks for working together!

Trust co-op agronomist advice

Paul Kvistad

We have gone from walking and riding beans through the glyphosate-only era to today.

Weed management on our farm the last few years has switched from all post-glyphosate spraying to using herbicides with other modes of action to combat glyphosate resistance.

Glyphosate-resistant waterhemp continues to be our toughest weed challenge.

Last year in soybeans, we sprayed Sonic herbicide preemerge, followed by a full rate of glyphosate when weeds had emerged and were still small (less than 4 inches high). For the cornfields, we used SureStart herbicide preemerge, followed by a reduced rate of Laudis and a full rate of glyphosate tank-mixed.

Before spring, I will sit down with my local co-op agronomists and go over plans for next year’s herbicide program. I will admit I spend very little time researching herbicides. I rely on my local co-op for recommendations.