Regional Update: June 7 to June 15, 2021

While some areas did receive some much-needed rainfall across the state, most areas received very little to no rainfall this past week. Consequently, it wasn’t hard to see lot of corn fields with leaves rolling this past week across the state. Lots of POST herbicide applications, sidedressing, and finishing putting up the first cutting of hay went on this week. Read on to see what ISU Extension and Outreach Field Agronomists are hearing or seeing in their respective regions across the state.

Northwest Iowa

Joel DeJong (Region 1): “In the NW corner of Iowa, this past week was hot and not humid – like for many of you. We did receive our first rain for the month of June – from 0.1 to 0.3 inch. From April 15 to today I have totaled 3.17 inches locally. Since May and June are the rainiest months, attitudes are lagging when we see those totals. Lawns went dormant over a week ago, and pastures appear to be doing the same. Alfalfa regrowth is occurring, and first crop tonnage was pretty good. Lots of spraying was done to keep alfalfa weevils from stopping regrowth. Corn is rolling more in the northern areas than the southern areas of the region and has been for several days.  However, most cornfields are now a good green color, and growth has continued. Most corn is at V6 and V7, but I have been in a few V8 fields that are well above my knees. Some narrow row cornfields are closing the rows. Beans are mostly V3 to V5, higher residue fields are “taking off” a little slower. Quite a bit of soybean weed control took place last week and will continue this week. Most were trying to avoid the hottest times of the day. There is concern about increased volatility in those dry, high temperature environments. We will likely find out how much of an issue that is in about two weeks.”

Paul Kassel (Region 2): “ Dry soils and the lack of rainfall is becoming a larger concern in this area. This ISU ICM Blog article considers current subsoil moisture, rainfall to date and average predicted rainfall for the rest of the season. Corn fields are rolling their leaves at 9:30 a.m. as a defense against the warm dry weather.  Many no-till soybean fields have been slow to develop because the crop residue kept the soil cool in the early spring. The current warm dry weather is now causing moisture stress in those no-till soybean fields since they apparently have less root volume than their conventional counterparts. Most POST herbicide applications in corn are now complete.  Many operations hope to complete soybean POST herbicide applications later this week. The hot dry weather has caused concern for the potential for dicamba off-target movement.  Farmers and agronomists are encouraged to check their non-dicamba tolerant soybean fields for off-target dicamba movement in late June.”

Northeast Iowa

Josh Michel (Region 5): “While some isolated pop-up showers Friday evening delivered up to 1 inch of precipitation in parts of Buchanan County, the rest of the region has seen less than 0.25 inch of precipitation over the past two weeks. This has understandably led to some concerns regarding diminishing soil moisture and increasing Growing Degree Days as temperatures continue to stay warm. Corn is generally around V5 to V6. Plants that incurred some frost damage from two weeks ago are rebounding nicely but are also starting to show some signs of heat stress. Nitrogen sidedressing and post herbicide applications are taking place in most areas. Soybeans are generally around V3 to V4 and are also slowly rebounding well from previous frost damage. The dry weather has allowed the first crop of alfalfa to get finished up, but there continues to be some concern that second crop regrowth may be slower than normal due to the lack of rainfall. Oats continue to look good, with around 40 percent headed out. Pastures are looking ok, but warm temperatures and the recent lack of rainfall are quickly slowing down the growth of many grasses. Recent field calls and questions have included: weed identification and post herbicide applications, alfalfa and small grain management, pesticide drift complaints, as well as several questions pertaining to heat stress on corn and soybeans.”

Central Iowa

Meaghan Anderson (Region 7): “A few lucky ducks got a shot of rain last Friday, but most of central Iowa received little or nothing. Crops are continuing to show a little more stress every day, and we’re hoping the rain chances in the forecast turn into something! Most corn is around the V7 growth stage and has fully come out of the “ugly duckling” look of the past several weeks. Most soybeans are around V3 and are short but appear mostly healthy. Many POST herbicide applications are wrapped up, so we’ll want to monitor fields in the 7-14 days after application to look for control issues related to weed size, herbicide resistance, or other problems like coverage and weather. Herbicide injury continues to be the most common discussion, whether it be from drift, tank contamination/clean out issues, or carryover. I saw my first field of cupped soybeans yesterday, so we’ll be on the lookout for cases of off-target movement from plant growth regulators, especially with the hot temperatures and low wind speeds potentially increasing risk for volatility and temperature inversions.”

East Central, Southeast, and South Central Iowa  

Rebecca Vittetoe (Region 8): “Most of EC area received little to no rainfall this past week. On the U.S. Drought Monitor most of the region I cover is now considered abnormally dry and part of Benton and Linn counties are considered to be in a D1 or moderate drought. With the hot temperatures last week, you could start to see corn leaves rolling in fields. A lot of POST herbicide applications were made this past week as well as people finishing putting up the first cutting of hay. Most corn is around the V7 stage and soybeans are mainly V3 to V5. I haven’t seen a soybean field at R1 yet but do pay attention to soybean growth stages as you are making your post herbicide applications and any label restrictions related to soybean growth stages. Questions or issues this past week have included floppy or rootless corn, corn showing more of a response to POST herbicide applications, sulfur deficiency symptoms in corn, weed identification, and herbicide injury.”

Virgil Schmitt (Region 9): “Rainfall during the last week in the counties I cover was generally less than 0.1 inch of rain except for amounts up to 1.5 inches near the Mississippi River. In general, temperatures during the last week in the counties I cover were 7 to 11 degrees above normal. Corn is V7 +/- one collar and soybeans are generally about V3. Sulfur deficiency symptoms in corn were very common last week. Moisture stress in corn is common along and north of Highway 30. Calls last week centered mostly around sulfur deficiency symptoms in corn, weed ID and management, and herbicide drift.”

Clarabell Knapp (Region 11): “This past week the area experienced scattered showers on Friday, producing up to 0.50 inch of rain in some places. Many farmers have continued working to get first cuttings of hay and alfalfa stands finished up in addition to continuing sidedress applications on early planted corn. Many corn fields are around the V7 stage and growing quickly with the warm temperatures and sunshine. Soybean fields are ranging from the VC to V4 stage. Oats remain looking good and early planted stands are around 50% headed out. Rising temperatures in addition to the recent lack of rainfall has slowed down pasture growth. Field calls have been driven by weed identification and controlling escapes, alfalfa and small grain management, and pesticide applications.”

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