Blog
Researchers at the University of Illinois recently published a paper identifying the PPO resistance mechanism in Palmer amaranth. It turns out that both Palmer and waterhemp have an unusual type of mutation providing resistance to the group 14 herbicides (PPO inhibitors). Rather than a...
A lot of farmers worked some long hours to complete fieldwork over the weekend because of the predicted rainy weather. There have been some heavy rains in extreme northwest Iowa early this week, but much of my area has missed those heavy rains. And, as a result, a lot of fieldwork was completed...
Plants with yellow flowers are a common sight in roadsides and other grassy areas as one drives across Iowa at this time of year. There's a good chance these plants are one of the weedy mustards (wild mustard, yellow rocket, hedge mustard, etc.), golden alexander, or wild parsnip. The mustards...
Yesterday, I was asked to help confirm an identification of a few beetles in a cornfield near State Center, Iowa. They ended up being striped and spotted cucumber beetles. Sometimes the striped cucumber beetle can be confused with western corn rootworm; however, it would be unlikely to see adult...
While I don't have a bucket list of weeds, it's always nice to find a new one. Today I had my first encounter with blue mustard (Chorispora tenella). Like all mustards, this plant has four petals, but the petals of blue mustard are pink to purple in color and very narrow, relative to...
A lot of soybean planting progress was made across the state this past week, as farmers tried to get ahead of this week's daily rain forecast. Most corn planting has been completed in Iowa, with 75% already emerged, according to the May 23 USDA Crop Progress Report....
Several corn fields in southeast Iowa are having disease issues this spring. After visiting with several ag retailers and farmers, I had Alison Robertson and Tom Kaspar, a plant physiologist with the USDA-ARS, out yesterday to look at some fields with issues. When we put all the pieces together...
I've had several questions on how long to wait following the frost event this past weekend before making a postemergence application. The answer depends on several factors, including 1) stage of corn at frost injury, 2) vigor of corn at time of frost, 3) weather following the frost, and 4)...
While driving to a field plot in Webster County earlier this week I saw a land roller being used in a field. My first thought: "If we have time to roll fields, why is there such resistance to the suggestion of mechanical weed control?"
Most farmers of my age have...
Scouring rush and field horsetail are two species in the Equisetum genus. These are primitive plants that produce spores rather than seeds, but they spread primarily by underground rhizomes. Until recently these two weeds were found primarily in roadside ditches, but the reduction in...
My area has a real range of conditions with corn planting 65-75% complete in the northwest part of my area. There is maybe 15% of the soybean crop planted in the northwest part of my area. The corn and soybean planting progress is 95%+ complete in the northeast part of...
Temperature is the key for both corn and soybean. Temperature below 28oF for a couple of hours will be lethal to growing tissue that has emerged. Temperatures between 28oF and 32oF will result in definite frost injury to above ground tissue. And temperatures...
As Merle Haggard said in his song, Under the Bridge, “you’ll find some great grub feedin’ here below.” I got a couple calls about grub injury in seedling corn last week and how to identify annual grubs (e.g., masked chafers and Japanese beetle) from true white grubs (May and June beetles) with a...
In the NW corner of Iowa it has, once again, been a wet week. There have even been localized rains as high as 6" for the week, although most received significantly less. Getting back to planting, it's has been difficult, and we are lagging the rest of the state in planting progress. We aren't...
Iowa has 80% corn planted as of May 8, according to Monday's USDA Crop Progress Report, up from 57% the previous week. The report shows that soybeans planted also made a notable jump from 7% complete on May 1 to 29%.
Many farmers were able to get back in the fields this weekend with a...
I've been getting a lot of questions about needing additional N for corn; growers are torn between putting some UAN in with herbicides vs. spreading urea. I’d caution them against using UAN as a carrier on emerged corn if they are applying herbicides. Yes, there are a few products that allow...
My home drinking water source comes from the Xenia Rural Water District. Depending on where you are located within the district, your water comes from an alluvial aquifer, or surface water from the Raccoon River or the Des Moines River. The water is treated and delivered to my home and,...
We have had a couple nice days and farmers are looking forward to some predicted good weather. Farmers are taking this all in stride since many have been through this before.
There has been a fairly abrupt line of heavy rainfall/planting progress in the area....
As of May 1, the USDA reported 57% of corn had been planted in Iowa. See below for area conditions and planting progress around the state from Iowa State University Extension and Outreach field agronomists. ISU Extension...
The United States has almost half of the corn crop planted for the season at 45% complete, according to the United States Department of Agriculture (USDA) Crop Progress Report on May 2.
The USDA reported 57% of corn planted in Iowa as of May 1, with the 5-year average being 28%. The...
Replanting is something we hope we don’t have to do a lot of, but if we do, there are some good resources to use to help make those decisions.
Stand assessment and replant decisions are often (OK, almost always) agonizing. It is hard to leave a stand that is below...
You should visit the newly formatted and revised Corn Nitrogen Rate Calculator (CNRC) website. The site has a new url ( http://cnrc.agron.iastate.edu/ ). For Iowa, there are now two regions, the Main Iowa area and a Southeast Iowa area (SEIA) – see...
We have had a couple windows of opportunity for fieldwork this spring. The week of April 10 to 17 saw a lot of fieldwork completed. Also, there was some fieldwork completed on April 23. I am referring to an area around Clay County and parts of Dickinson and Buena Vista counties.
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Accelerated, early planting in some parts of the state increases pressure on applicators of preemergence herbicide to speed up sprayers to cover a larger numbers of acres. Increased speeds increase boom pressure for existing nozzles, and can tempt applicators to increase boom height. Both...
Corn typically requires 90 to 120 Growing Degree Days (GDD) from planting to emergence. Of course this GDD range assumes adequate soil moisture and varies with planting depth, tillage system and residue cover. As a rule of thumb, if 120 GDD have accumulated since planting and seedlings haven’t...