Regional Update: June 5 - June 13, 2023

June 13, 2023 12:17 PM
Blog Post

The dry conditions across the state can be attributed to a lot of the issues or questions ISU Extension and Outreach Field Agronomists heard about or received this past week including issues like herbicide carryover, nutrient deficiencies, and showcasing compaction issues in fields not just from field activities this year, but previous years as well. Read on for more specifics about what’s happening around the state. 

Northwest Iowa

Leah Ten Napel (Region 1): “It is my first growing season serving as the Extension Field Agronomist for NW Iowa, and I don’t think it’s one I will ever forget. So far June has been full of field calls that are making everyone scratch their heads. Many issues we are finding, in both corn and soybeans, are related to carryover issues from last year's crop. I am also seeing a significant amount of nutrient deficiency. I haven't gotten too many reports on insect or disease damage. Make sure to scout fields following post herbicide applications for any weed escapes. Corn plants are staging from V5 to V8, and soybeans V2 to V4.”

Soybean plant showing clopyralid carryover symptoms. Photo courtesy of Leah Ten Napel. 

Corn plants with sulfur deficiency. Because sulfur deficiency gives the plant a yellowish cast, it is often confused for nitrogen deficiency. However, nitrogen deficiency shows up on the lower leaves whereas sulfur deficiency shows up on the newer leaves with interveianl choloris. Photo courtesy of Leah Ten Napel. 

Gentry Sorenson (Region 2) “Last week scattered showers occurred over the area. Rainfall of over an inch fell in parts of the western half of region 2 with lesser amounts down to a couple of tenths occurring to the east in the region.  Field work last week consisted of post herbicide spraying.  Post applications of herbicides have been completed in many corn fields, with herbicide applications now focused on soybeans. Corn ranges from V6 to V8, with soybeans ranging from V2 to V3. It has been a busy week with farm calls and phone calls. Some of the issues observed have been related to the dry conditions of the past year. Farm calls and phone calls consisted of crusted soil in soybean fields, replanting decisions, herbicide drift questions, herbicide carryover, potassium deficiency in corn fields, and iron deficiency chlorosis in soybean fields.”

Northeast Iowa

Josh Michel (Region 5): “Isolated light rain showers delivered small amounts of precipitation throughout Northeast Iowa over the past week. Generally, most of the area received around 0.10 inch, although a few isolated areas were able to receive up to 0.25 inch. Because of the below average precipitation, plants are starting to show signs of stress, especially on lighter soils. That being said, crops are continuing to grow, just at a slower than normal pace. Most corn fields are currently V3 to V6. Post herbicide and side dressing applications continue taking place as the weather allows. Recent corn-related field calls have centered around herbicide injury and carryover, anhydrous burn, nutrient deficiencies, compaction issues, and early season insect damage. Soybeans are mostly V1 to V2, as post herbicide applications continue taking place across most of the region. Similar to corn, most field calls have centered on herbicide injuries and early season insect damage. Forages and small grains are beginning to show signs of moisture stress as well. There are also some continued concerns about limited alfalfa regrowth. Alfalfa weevil larvae are still being found in some fields, and potato leafhoppers are beginning to show up as well. Pastures remain in fair to good condition, but many cool season grasses are starting to slow down due to limited rainfall. Approximately 60 percent of the oats are headed out and early season harvest has started in many areas.”

Northeast Iowa

Terry Basol (Region 4): “Despite the drier climate for NE Iowa, crops are holding in there. Corn ranges from V4 toV6. Post-emerge herbicide applications are completed as well as side-dressing nitrogen. Leaf rolling is starting in some of the fields with lighter soils due to dry topsoil conditions. Most of the corn in the area is starting the transition of the nodal root system taking over as the primary for water and nutrient uptake. Soybeans are in the V3 to V4 stage for the area, and farmers have been busy with post-emerge herbicide applications this past week. I have noticed some bean leaf beetle feeding, but the defoliation percent has been low, and the soybeans have been able to stay ahead of them without warranting a treatment. According to the National Agricultural Statistics Service (NASS), as of June 11, 64 percent of the oats have headed out. First cutting of alfalfa is pretty much wrapped up for NE Iowa, and recovery has been slow due to the dry conditions. As far as precipitation, the area in general is dry and needing a good rain event for the crops. According to the Iowa Mesonet, the NE IA Research and Demonstration Farm here at Nashua has received 0.11 tenth of rain since June 1st.

East Central, Southeast, and South-Central Iowa

Rebecca Vittetoe (Region 8): “This past week brought another week with spotty and limited rainfall with totals ranging from a tenth to about 0.5 inch. Corn is mostly V6 to V7, and soybeans V2 to V4. I have spotted soybean plants flowering here and there in some of the earlier planted fields. There were some corn fields rolling leaves late last week and on Saturday. Post herbicide applications in corn have basically wrapped up, and attention is turning to post applications in soybeans now. Forage growth has really slowed down with the dry conditions and warmer temperatures. I’ve had two isolated calls regarding armyworms causing damage in pastures. Most of the concerns, questions, and fields calls this last week have been related to the dry conditions and have included potassium and sulfur deficiencies in corn, compaction issues, and herbicide carryover.”  

Corn plant struggling due to compaction from a hard pan (horizontal roots) and sidewall smearing at planting (tomahawk roots). Photo courtesy of Rebecca Vittetoe. 

Virgil Schmitt (Region 9): “Rainfall in the last week in the counties I cover has been generally less than 0.5 inch except for far eastern Clinton County. Rainfall has been very hit-and-miss with some places receiving no rainfall. Shallow-rooted grasses, such a bluegrass continue to go dormant in many places. First cutting hay harvest is, for all practical purposes, complete. Re-growth continues to be slow. There are a few lingering alfalfa weevils, and some potato leafhoppers can be found. Most corn is V6 to V7 and looks good to excellent except in areas of coarse soils, clay soils, and compacted areas. Postemergence spraying is mostly complete. Most soybeans are V2 to V3 and look good to excellent except for areas of coarse soils, clay soils, and compacted areas and areas where crusting issues have lowered populations. Phone calls, emails, and field visits last week mostly involved sulfur deficiency symptoms in corn, compaction issues in corn, and herbicide drift.”


Clarabell Probasco (Region 11): “Much of the corn fields across south central Iowa are found in the V7 stage with soybean fields around the V3 stage. The weekend brought a few rain systems that came with extended periods of rainfall for much of the area. Even with the larger systems and the longer time they occurred over a location, most areas only received a few tenths of rainfall. Still, the moisture was well received and coupled with the cooler temperatures, gave the crops a nice break from the hot and dry days we had been experiencing.  Many post soybean herbicide applications have been taking place. Not much insect pressure has been seen or reported yet in crops or forages. Forage systems that have been grazed or harvested for hay are still short for regrowth, again due to the lack of moisture. The majority of field calls have been in regards to issues arising from the lack of moisture.”

Check out the map below to find your local ISU Extension field agronomist and find their contact information here


Rebecca Vittetoe Field Agronomist in EC Iowa

Rebecca Vittetoe is an extension field agronomist in east central Iowa. Educational programs are available for farmers, agribusiness, pesticide applicators, and certified crop advisors.

Areas of expertise include agronomy, field crop production and management of corn, soybeans, and...