In the last two weeks, field activities across the state have included planting wrapping up, replanting soybeans in fields with thinner stands, side-dressing nitrogen in corn, applying post-emergence herbicides, and putting up the first cutting of hay. Common issues and concerns reported by ISU Extension field agronomists during this period included weed pressure in fields, herbicide damage, anhydrous ammonia injury in corn, and sulfur deficiency symptoms in corn. Read on for more specifics about what is happening across the state from your ISU Extension and Outreach field agronomists.
Leah Ten Napel (Region 1):
Cherokee, Ida, Lyon, Monona, O'Brien, Osceola, Plymouth, Sioux, Woodbury counties
“Northwest Iowa has received anywhere from 1 to 3 inches of precipitation in the last two weeks, which was much needed by the corn and soybean crops. Very little emergence issues showed at the beginning of the growing season, but as surrounding plants are starting to flourish, problem areas in the fields are being highlighted. Problems are coming from compaction, equipment or herbicide issues. No real problem trends are forming. Weeds are making their second rush of emergence, and many second pass applications are being made, especially on corn fields. Little insect issues have been reported.”
Angie Rieck-Hinz (Region 3):
Cerro Gordo, Franklin, Hamilton, Hardin, Humboldt, Webster, Worth, Wright counties
“Crop conditions seem to be improving across NC Iowa. Corn is V2 to V6, soybeans are VC to V2, some pushing V3. A little bit of rain helped struggling soybeans to emerge late last week. Post-applications of herbicide started again late in the week of May 26th. Nitrogen side-dressing has started and there was a lot of hay cut right after the Memorial Day weekend. All in all, the phone was relatively quiet, but I did receive a few calls about herbicide drift complaints to trees and landscaping plants on farmsteads and acreages.”
Terry Basol (Region 4):
Benton, Black Hawk, Bremer, Butler, Chickasaw, Floyd, Grundy, Howard, Mitchell counties
“The last couple of weeks have provided farmers nice field conditions to finish up planting both corn and soybeans for the area. Corn ranges from V1 up to V4 for most of the acres, and soybeans range from VE toV1. Both crops look really good for NC/NE Iowa. Field operations include first post emerge herbicide applications as well as side-dress nitrogen applications for the corn crop. First cutting of alfalfa has begun with stands looking very good for quality. As far as precipitation for the last couple of weeks, we received a nice rainfall for the area the week before the Memorial Day weekend. According to the Iowa Mesonet, the NE Iowa Research and Demonstration Farm at Nashua has received 2.01 inches of rain from May 19 through May 22, and 2.34 inches for the month of May.”
Josh Michel (Region 5):
Allamakee, Buchanan, Clayton, Delaware, Dubuque, Fayette, Jones, Linn, Winneshiek counties
“In-between some light scattered showers last week, farmers were able to continue post herbicide applications, first cutting alfalfa harvest, and even start some side-dressing applications. In general, most of the region received anywhere from 0.10 to 0.25 inch of rainfall. This light rain was welcomed as temperatures are beginning to warm up and small seedlings are setting their initial root systems. Some of the early planted corn is V3 to V4, while the later planted corn is around VE to V1. Early planted soybeans have reached V2, while later planted soybeans are around VC to V1. Approximately 25% of the oats are starting to head out. The second half of first cutting alfalfa harvest was also completed for those who didn’t get it cut a couple weeks ago. There were some reports of increasing alfalfa weevil feeding, but recent cuttings should keep their populations in check now. Pastures continue to look good and anticipated rainfall this week should keep them going strong. The majority of field calls this past week centered around weed identification and management, adjusting herbicide programs, and assessing various herbicide drift and crop injury reports.”
Meaghan Anderson (Region 7):
Boone, Dallas, Jasper, Madison, Marshall, Polk, Story, Tama, Warren counties
“Most of my counties received substantial rainfall the week before last, with totals higher than 5 inches in some places. Western Dallas and Boone counties received less than 2 inches. Corn is now anywhere from emerging to about V5-6. Most stands look quite even, though I’ve seen a few fields that were planted in poor conditions in late April/very early May and are emerging very unevenly. Some corn is going through that “ugly duckling” stage where the plants appear yellow or uneven as the nodal roots are taking over. Soybeans are emerging to about V2. Aside from early issues with preemergence herbicides and soil crusting, I haven’t really received many phone calls about soybeans this spring. The wind, rainfall, and following cooler conditions left some corn looking awfully tattered and some even tilting sideways ahead of POST herbicide applications, which resumed a little over a week ago. Phone calls have been about sulfur deficiency in corn, anhydrous ammonia burn, herbicide drift and tank/boom clean out issues. Phone calls have started about POST herbicide control failures on waterhemp, so make sure to scout fields in the 7 to 10 days following the POST herbicide application to make sure weeds are dying!”
Rebecca Vittetoe (Region 8):
Iowa, Jefferson, Keokuk, Poweshiek, Washington, Johnson counties
"Over the past two weeks, rainfall totals have ranged from 1.5 to 2.5 inches across the counties I cover, with most of that rain falling the week prior to Memorial Day. Corn growth stages range from V1 to V7, while soybeans range from VE to V3. The earliest planted corn has mostly moved past the “ugly duckling” stage and is really starting to take off. On the soybean side, thin soybean stands in some fields have been a concern. As a result, some fields or portions of fields were replanted. In addition to soybean replanting, other field activities have included side-dressing nitrogen in corn, POST herbicide applications, chopping rye cover crop fields, and harvesting the first cutting of hay. Most of my calls have focused on thin soybean stands, weed identification, herbicide injury, and weed management."
Virgil Schmitt (Region 9):
Cedar, Clinton, Des Moines, Henry, Jackson, Lee, Louisa, Muscatine, Scott counties
“Most of the area I cover received two to four inches of rain during the week before Memorial Day and 0.5 inch or less since Memorial Day. Most corn is V2 to V4 and generally looks good. Soybeans are mostly VE to V2 and generally look good. Hay and pastures look good and the harvest of first cutting hay progressed rapidly during the last week and is nearly complete. Some smooth bromegrass heads in ditches and fence lines are turning brown due to stalk borer injury. Wild parsnip in ditches is putting on a display generally south of Highway 30.Calls during the last two weeks have mostly centered around uneven corn, soybean replant decisions, and weed management.”
Aaron Saeugling (Region 10):
Adair, Adams, Cass, Clarke, Decatur, East Pottawattamie, Fremont, Mills, Montgomery, Page, Ringgold, Taylor, Union, West Pottawattamie counties
“Warm weather when available has allowed to corn to take off. The larger corn is in the V8 or larger stage. Post emerge applications and side dressing are wrapping up on corn. Soybeans are a different story. Soybeans struggle with cool, cloudy days and isolated crop response to herbicides applied under cool, cloudy conditions. Dry conditions persist in most of SW Iowa. We ended May with only 1.75 inches of rain, and the start of this week only 0.20 inch of rain. Much of the hay has been mowed the last 10 days. We need to remember that June is our wettest month of the year. Nebraska has reports of soybean gall midge emergence, so be on the lookout for that injury.”
Logan McCrea (Region 11):
Appanoose, Davis, Lucas, Mahaska, Marion, Monroe, Van Buren, Wapello, Wayne counties
“Over the past two weeks we have seen many things occurring with corn and soybean planting wrapped up, first cutting hay being put up, and some precipitation, warmth, and sunshine to go along with it all. Those last few are helping push along the crops and have south-central Iowa sitting with corn that ranges from VE to V7, and soybeans ranging from VE to V2. The second half of first cutting hay was put into motion after the midpoint of last week, and most seem to be pleased with the quality. Post emerge herbicide applications have been going out over the past couple weeks when the ground conditions and wind have allowed us. Most calls recently have been around weed ID for both crop field/pasture and post emerge herbicide questions.”
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- Field Agronomist in EC/SE Iowa