Blog
There is no question that dicamba injury across the Iowa landscape in 2020 is the most extensive it has been since the introduction of dicamba in the 1960s. ISUEO field agronomists and commercial agronomists in several areas of the state report nearly all non-dicamba resistant soybean are...
Limited rainfall and the warmer temperatures causing crop stress, herbicide injury in soybeans, soybean gall midge, and Japanese beetles were some of the common issues or concerns that ISU Extension field agronomists saw in fields across the state this last week. Read on to see what’s happening...
Extension specialists in Iowa and Minnesota are again collaborating to provide a series of short webinars for farmers, ag professionals, Extension personnel and other interested parties from July 14 to July 23. The theme is “Essential Row Crop Management" for summer 2020, with a focus on key...
Nearly 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...
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...
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...
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,...
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....
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...
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).
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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...
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...
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...
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...
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...
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...
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...
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...
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 (...
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...
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...