Regional Crop Update: July 13 - 21, 2026

The last week was a hot and dry one for most of the state. Storms did roll across the state Monday into Tuesday of this week that brought some rain but also strong winds and hail. While disease pressure remains low in both corn and soybeans, southern rust has been confirmed in four counties in Iowa. In the fields southern rust was found in, it was found at very low levels. Read on for more specific on what ISU Extension field agronomists are hearing and seeing in fields around the state. 

Leah Ten Napel (Region 1)

Cherokee, Ida, Lyon, Monona, O'Brien, Osceola, Plymouth, Sioux, Woodbury counties

“Crops are continuing to progress nicely, but dry spots are showing up in areas. A nice rain would have a big impact on both corn and soybeans. Many fungicide applications are being made to corn with disease pressure remains low in both crops. Some insect pressure starting to pop up in soybeans. Weed control is still looking good in most crop fields. Weed pressure in pastures is high in areas. Oat fields are being harvested. Pastures and hay fields are holding okay, but would benefit from some precipitation.” 

Gentry Sorenson (Region 2)

Buena Vista, Clay, Dickinson, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas, Winnebago counties

“We had a storm roll through northern Iowa on the July 20. Rainfall from a trace up to 2 inches fell across the northern tier of counties. Strong winds and some hail were also reported. In an area of Hancock County wind green snapped and severely lodged the corn in the path of the storm. Currently on average corn is at the R2 growth stage. Soybeans are at the R2 to R3 growth stage, and now is a good time to start scouting for soybean aphids. Alfalfa fields were baled across the area this week. Phone calls have been about fungicide timing, corn diseases, waterhemp and soybean aphids.” 

 Angie Rieck-Hinz (Region 3)

Cerro Gordo, Franklin, Hamilton, Hardin, Humboldt, Webster, Worth, Wright counties 

“On average, most corn is R2 (blister) with some areas pushing R3 (milk). At R2, corn has reached its maximum height, max vegetative dry matter and max ear length. Even with hot temperatures, it appears we have had good pollination, but tip kernel abortion, which happens between R2 and R3, could be an issue in those areas that have remained on the dry side. Disease incidence and severity remain low but continue scouting to make those fungicide input decisions. Soybeans are R3 and a few more diseases are starting to show up in soybeans. I have most commonly noted Phytophthora root and stem rot and bacterial blight. I have not found soybean aphid and have not had any reports of soybean aphid. Rainfall on July 20 ranged from 0.37 inch near Eagle Grove to 2.07 inches north of Mason City with reports of hail, wind, and some flattened crops. Rainfall to date for the month of July is right at normal across reporting stations in the counties I cover, but earlier season lack of rain has still left areas around Calhoun County at a deficit of just over 6 inches for the growing season according to the Iowa Mesonet.” 

Terry Basol (Region 4)

Benton, Black Hawk, Bremer, Butler, Chickasaw, Floyd, Grundy, Howard, Mitchell counties 

“For North Central – Northeast Iowa, corn and soybeans are looking relatively good. Corn is currently in the VT stage, and soybeans are primarily in the R2 stage. We have been seeing some unevenness in tassel emergence. Some of the likely culprits that can cause this are planting into cold or wet soils (followed by dry, hard soil, stunting root formation), compacted soils, sidewall compaction, shallow planting depth, and heavy crop residue. As the corn is now in the VT stage, farmers are currently making fungicide decisions. It’s important to scout corn fields for foliar diseases to determine if a fungicide application is warranted. To help with making decisions, check out this ICM Blog “Fungicide decisions in 2026”. Some of the foliar diseases that have been reported for the area include tar spot, Curvularia leaf spot, bacterial leaf streak, gray leaf spot, and southern rust (as of July 21 only found in four counties in Iowa and low in incidence). To check on what’s being found in fields, go to the Crop Look Out Tool on the Crop Protection Network webpage. For most of the soybean acres in the area, herbicide applications have wrapped up. Continue to scout for insect activity including defoliators (Japanese beetles, grasshoppers, and bean leaf beetles) as well as soybean aphid a little later. Oats have been harvested or are in the process of being harvested in the area. As far as precipitation, we had a dry week last week, but received good rainfall the first week in July, along with the 1.98 inches of rain received yesterday (July 20). According to the Iowa Mesonet, the Northeast Iowa Research and Demonstration Farm near Nashua received 18.69 inches of rain since April 1 for the growing season, and 6.0 inches since July 1. Looking at the map below, precipitation departure (in inches) ranges from over 6 inches above average to about 1.5 inches below average for the area to date for this growing season.” 

Josh Michel (Region 5)

Allamakee, Buchanan, Clayton, Delaware, Dubuque, Fayette, Jones, Linn, Winneshiek counties

“Over the past two weeks, crops have been advancing very quickly due to the continued rainfall and very warm temperatures. While most of the region has received around 0.50 to 0.75 inch of rainfall, some isolated areas have received up to 1.5 inches of precipitation. In general, most of the corn has reached VT/R1, and soybeans are around R2 – R3. Disease pressure continues to remain low at this time. Small grains and forages continue to look good. Many oat fields are getting harvested with reports of average to slightly above average yields and test weights. The tail end of second crop alfalfa is getting put up, while some dairy operations are beginning their third cutting. The majority of field calls have centered around herbicide drift and injury, as well as scouting for crop diseases.”

Rebecca Vittetoe (Region 8)

Iowa, Jefferson, Keokuk, Poweshiek, Washington, Johnson counties 

“Last week was a hot and dry one. On Saturday, there was a pop-up shower that brought some rain to parts of Keokuk, Washington and Jefferson counties, but totals were less than 0.5 inch. Monday some storms also rolled through my region. Rainfall totals ranged from a trace in Keokuk and Jefferson counties to 1.7 inches in Johnson County. Corn mostly ranges from VT/R1 to R2, and soybeans are mostly R2 – R3. Disease pressure remains low in both crops. In corn gray leaf spot, bacterial leaf streak, northern corn leaf blight, tar spot, and most recently southern rust have been reported. And in soybeans, bacterial pustule, septoria brown spot, and Phytophthora root and stem rot have been reported. Continue to scout fields for disease pressure to help make fungicide decisions. Adult corn rootworm beetles and Japanese beetles are present, and this last week I also started to notice more grasshoppers as well. Now is a great time to dig corn roots and evaluate for rootworm feeding. Questions this last week were mainly on diseases present in fields and foliar fungicide decisions.” 

Virgil Schmitt (Region 9)

Cedar, Clinton, Des Moines, Henry, Jackson, Lee, Louisa, Muscatine, Scott counties

“During the last week, the counties I cover have generally received zero to 0.3 inch of rain except parts of Scott County received nearly 0.5 inch. Most corn fields are VT/R1 to R2 and generally look good. Little disease is present. Most soybeans are R2 and also look good. Again, little disease is present. Small grains and forages also are doing well. Second cutting hay is mostly complete and most did not get rained on. Some have reported that it is the largest second cutting hay they have ever had. Winged grasshoppers are present. Calls last week mostly centered around herbicide drift and fungicide applications on corn.” 

Aaron Saeugling (Region 10)

Adair, Adams, Cass, Clarke, Decatur, East Pottawattamie, Fremont, Mills, Montgomery, Page, Ringgold, Taylor, Union, West Pottawattamie counties 

“Conditions in dry areas continue to miss rainfall and last week’s hot weather has advanced crop maturity.  Corn ranges from R1 to R3 and is doing well despite the warm weather. Replanted corn in Taylor, Adams, Union counties is behind. Fungicides are actively being applied this week. Disease scouting has revealed low incidence at this point with gray leaf spot, and bacterial leaf streak being the more common diseases present. The two southern tiers of counties have had more rainfall, so keep watch this week for any further disease development. Overall, insect activity is low. Pockets of Japanese beetles, western bean cutworm and corn rootworm activity can be found. Soybeans are tolerating the heat and progressing rapidly for early April planted beans. Where rainfall has occurred, this will be helpful for pod development. Precipitation would benefit later maturity soybeans as well as later planted beans. Most common diseases in soybean fields include bacterial pustule and septoria brown spot. However, both are found at low levels.”