Blog
Subscribe to RSS FeedNearly 20 years ago I summarized research from the University of Minnesota investigating factors that influence volatilization of dicamba (Behrens and Lueschen. 1979. Dicamba volatility. Weed Sci...
Erin Hodgson
July 2, 2020 3:27 PM
After visiting several ISU Research and Demonstration Farms this week, our summer crew started seeing caterpillars in soybean plots. Many species are possible at once, but rarely do they cause economic injury in Iowa. Defoliation must exceed 20% after bloom to justify a rescue foliar treatment...
Rebecca Vittetoe
June 30, 2020 10:38 PM
Lack of moisture in the western part of the state to excess moisture in the eastern part of the state, herbicide injury in soybeans, and bacterial leaf streak in corn were the common issues or concerns that ISU Extension field agronomists saw and heard about this past week. Read on to see what’s...
Meaghan Anderson
June 29, 2020 6:46 PM
Bob Hartzler
June 29, 2020 6:46 PM
We’ve seen more herbicide injury to soybean than I recall in past summers, resulting in questions about determining the source and reasons for the damage. This ICM Blog will share some tips on identifying herbicide injury we’ve seen this summer in soybean fields.
Crop injury may be caused...
There have been a few fields where topramezone – the active ingredient in Impact and Armezon – carried over from an application last June – and is injuring this year’s soybean crop. Other agronomists have reported carryover of other Group 27 herbicides on soybean this year (mesotrione,...
Rebecca Vittetoe
June 23, 2020 10:13 PM
Spotty rainfall across the state, herbicide drift, “Rapid Growth Syndrome” in corn, and shorter beans were common issues or concerns that ISU Extension Field Agronomists saw and heard about this past week. Read on for more specifics about what’s happening in different regions across the state....
Mark Licht
June 23, 2020 9:40 AM
Many farmers and agronomists are noticing short soybean this spring. Some are pondering if there is something that can be done to spur some additional growth as flowering is fast approaching, if not already begun. The surprise with short soybean is that planting was timely. The unfortunate...
Alison Robertson
June 22, 2020 3:27 PM
Over the weekend there have been several reports of bacterial leaf streak (BLS) of corn in eastern Iowa. The infections also appear to be quite severe (Figure 1).
...
There have been reports of flowers in the earliest planted soybeans, and I observed them in NW Iowa late last week. That means these beans are entering the R-1 stage of development. If you have a history of white mold in your soybeans and are considering treatment for reducing the impact of this...
Terry Basol
June 18, 2020 4:40 PM
Temperature Inversions
It is never recommended to spray a pesticide when a temperature inversion exists, and many labels provide guidelines to follow in order to avoid applications during one. This blog will discuss what temperature inversions are, why they can be...
Erin Hodgson
June 18, 2020 3:56 PM
Today, with Ashley Dean and Angie Rieck-Hinz, I met Warren Pierson at FEEL to look for corn rootworm larvae. I predicted peak corn rootworm egg hatch for central Iowa this week based on accumulating degree days. We had no trouble finding larvae in refuge corn, ranging from ¼ to ½ inches in...
The growing season is in full swing, and as Iowa growers and gardeners move along toward the Fourth of July, it is important to remember that the COVID-19 precautions continue to alter operations at the Iowa State University Plant and Insect Diagnostic Clinic (PIDC).
The PIDC continues to...
Rebecca Vittetoe
June 16, 2020 9:26 PM
Reports of soybean gall midge adults emerging, rainfall or lack of rainfall, weed management concerns, and herbicide drift were some of the common issues or concerns that ISU Extension field agronomists saw or heard about this past week. Read on for more about what's happening in specific...
Sotirios Archontoulis
June 15, 2020 10:18 AM
Mark Licht
June 15, 2020 10:18 AM
Zachary Clemens
June 15, 2020 10:18 AM
Radiation is down up to June 1 according the latest FACTS extrapolations.
The springtime decreases in radiation—especially in May—could have caused yellowing corn leaves and slowed down leaf appearance rates (radiation and moisture play a role in phenology, even though temperature is the...
Erin Hodgson
June 12, 2020 3:45 PM
Today, ISU entomology graduate student, Mitchell Helton, captured the first adult soybean gall midge in Iowa. Just a few hours later, cooperator Lauren Botine (Corteva Agriscience), collected another adult. Currently, our traps are placed in fields infested with soybean gall midge in 2019. There...
Rebecca Vittetoe
June 9, 2020 8:46 PM
Sidedressing nitrogen, post emergence herbicide applications, and putting up hay were the main field activities that took place over this past week across the state. Some of the issues ISU Extension and Outreach field agronomists saw this past week ranged from dry conditions in the western part...
Yellowing of corn plants early in the season can be confusing to diagnose. And in some conditions there may be a period of time after corn emergence where small corn just does not look good. There can be a number of causes for plant yellowing. An example is the description in a recent ICM Blog...
Bob Hartzler
June 9, 2020 1:59 PM
Meaghan Anderson
June 9, 2020 1:59 PM
One important benefit of cover crops to our production system is providing an alternative selection pressure on weed populations. Cereal rye has the best potential to suppress weeds because it accumulates more biomass than other cover crop species. Weed suppression is closely related to the...
Bob Hartzler
June 5, 2020 6:47 AM
Prashant Jha
June 5, 2020 6:47 AM
Meaghan Anderson
June 5, 2020 6:47 AM
Numerous herbicides registered for postemergence use on Xtend soybean have excellent activity on important weeds of Iowa’s soybean fields. Unfortunately, herbicide resistance in waterhemp is widespread to the herbicide groups active on this weed: Group 2 (ALS inhibitors), 9 (glyphosate) and 14 (...
Alison Robertson
June 4, 2020 9:52 AM
Earlier this week I was out in corn fields "helping" my lab crew collect disease data. The corn was not looking great but hopefully it has perked up with the past few days of sun and warmth. I know I have!
I noticed in my corn-on-corn fields anthracnose leaf blight on the lower leaves of...
Ashley Dean
June 3, 2020 9:59 AM
The trapping season for true armyworm (TAW) and black cutworm (BCW) has come to an end. We appreciate our cooperators for tirelessly checking traps the last two months and reporting their captures so we can provide the most accurate scouting information for these pests. To recap, we had 36...
Rebecca Vittetoe
June 2, 2020 3:57 PM
The crops have really started to take off this past week with the warmer temperatures. While rainfall limited field activity in parts of the state, where fieldwork could be done many got started on sidedressing, post herbicide applications, and putting up hay. Yellow and uneven corn, weed...
Although there is no evidence of widescale problems with carryover injury to corn or soybean, ISUEO field agronomists have received a few reports. The potential for carryover injury is determined by several factors, including: 1) persistence of the herbicide, 2) herbicide rate, 3) soil...
Terry Basol
June 1, 2020 1:45 PM
In order to keep up with any changes and updates on pesticide uses and restrictions from year to year, it’s important to thoroughly read the label before any applications are made, even if the same product was used the previous year. If nothing else, it helps to refresh our memory on the...
Webinar to be offered on June 3 “Ongoing Impacts from the 2019 Harvest and Early 2020 Crop Forecast”
Erin L Bowers
May 28, 2020 2:58 PM
Charles R Hurburgh
May 28, 2020 2:58 PM
Iowa State’s Dr. Charles Hurburgh will be presenting on the topic “Ongoing Impacts from the 2019 Harvest and Early 2020 Crop Forecast” as an installment in the Grain Elevator and Processing Society’s...