From the Week of August 7, 2023

The one-stop-shop for everything you need to know about what’s happening this week in your fields.

This week’s featured agronomists are:

Dave Richter – Belle Plaine
Gregg Gustine – Pine Island
Chad Wiersma – Morristown
Tye Anderson – Lewiston
Eric Soley – Ellsworth


Scroll down to hear from your local agronomist, and click for contact info!

Everyone at Ag Partners wishes you a safe & enjoyable rest of summer! We will return this Fall with more Weekly Agronomic Updates.

Belle Plaine – Le Center – Le Sueur


Dave Richter

As the summer winds down its Fair Season and cooler nights are here. Some areas are finally getting some timely rains which has given the Soybean crop a nice boost. We have seen an increase in blossoms on the top of the plants that we want to help protect. The Aphid populations have increased and we need to keep scouting. The Aphid threshold is 250 / plant with numbers increasing at these levels it would be the time to schedule spraying. With the dry weather we also need to be scouting for spider mites, look for an area with top of leaf stippling and yellow. Lay a white piece of paper on the ground and shake the plant, if you see pin head like objects moving on the paper this would indicate mites. You would need an insecticide that would handle both mites and aphids. You can call your local agronomist for the most effective control.

Pine Island – Cannon Falls – Goodhue – Lake City


507-272-3468Gregg Gustine

August is a good time to get your alfalfa ready for next year. You should apply a minimum of 200 pounds of potash after your August cutting. This will enhance the plants ability to store carbohydrates in the roots and reduce the risk of winterkill.

Digging roots at the end of the season will help you decide when to take a field out of production. A field with advanced crown rot will probably have lower yields next year and the diseased plants have a high risk of winterkill. Fields with less than four plants per square foot should be rotated out of production.

Walk your corn fields now to assess root worm pressure for next year. Silk clipping by rootworm beetles can affect pollination if it occurs at the right time. The field in the picture below had extremely high root worm pressure with all silks clipped and some kernel damage at the tip of the ear. An insecticide can be added to your fungicide application next year to lower beetle populations.







Morristown – Wanamingo – Kenyon


Chad Wiersma

Where did the summer go? As we enter the second week of August it’s hard to believe we are here already. The rain this past weekend was for most of the area a crop saver; things were starting to really show stress by the end of Friday/Saturday. Most of the area I work in received around a half inch all the way up to 2 inches. It’s amazing how much better the crop looks with rain, humidity and a little lower temps this week. Fungicide applications are mostly wrapped up, so we are just monitoring fields that didn’t get insecticide with the fungicide application. A few areas are seeing aphid counts increase. Spider mites were starting to concern me before the rain. If we can catch more rain soon that should keep them at bay. We are finding disease starting to show up in the soybeans. The stress of challenging emergence, as well as dry and hot conditions seems to have put a lot of pressure on the soybean crop. We aren’t finding much for disease pressure in corn, this includes tar spot. We will continue to watch for tar spot in corn and make sure insects in the soybeans don’t get out of control.  Enjoy what is left of summer & see you this fall!

Elgin – Lewiston – Stewartville

563-380-3347Tye Anderson

This year more than ever we are seeing how crucial it is to not only use the correct chemistry, but also enough chemistry. Late season escapes are starting to pop throughout some of the territory in both corn and beans. In some cases, we can tell a major difference in one pass vs. two pass. Getting a solid pre-emerge herbicide applied has shown to be a key to keeping corn fields clean in late season. In one pass situations, we have one shot all year to keep things clean. In a very wet year, we can lose the residual just like a vehicle runs out of gas. In a dry year, the residual doesn’t reactivate and we get escapes. Being able to layer residual with two passes has made a massive difference. Two-pass by far is more effective in the total suppression of weeds in your fields. Below is a slide showing the number of seeds each weed produces in a year. Below that in the orange shows the viability of those seeds in future years. Best of luck in the rest of the growing season and I wish everyone a safe harvest.


715-273-5380Eric Soley


It’s fair week in Pierce County, Wi and just as the 4-H kids get the opportunity to have their projects evaluated by judges it’s also a perfect time for us to judge the performance of our herbicide plans from this growing season. Here are a few of my observations and thoughts for next year:


  1. Mother Nature is still the boss. It doesn’t matter how perfect of a plan we design and execute if we don’t receive timely rains to activate residuals. Often times we got our pre-emergent herbicides down and followed it with a timely second pass but then had to wait, sometimes weeks, for rain.
  2. If Mother Nature is the boss, then waterhemp is second in command. It’s hard enough to kill this weed under ideal conditions but trying to eliminate it during the dry month of June proved challenging. Many times we curled them up and turned them brown only for them to recover and make a victorious appearance above the soybean canopy in August.
  3. If your bean fields are loaded with waterhemp then your corn field right next to it that received a one pass program has escapees in at as well. Those are just out of sight, out of mind.
  4. Giant Ragweed has been dominated in the bean fields with the use of Xtend and Enlist traits. Controlling them in the soybeans has greatly reduced their pressures in the corn fields.

Final judgement: In our territory corn fields are going to have to start getting a 2 pass herbicide program. There’s more waterhemp in these corn fields than we realize and not controlling them in the corn only makes it more difficult in the beans.