Regional Update: April 23 - May 7, 2024

Recent rain events have put a delay on much planting progress and other field activities across the state of Iowa. Planting considerations, alfalfa weevil, cover crop termination, and weed management have been some of the common questions or topics reported by ISU Extension and Outreach field agronomists over the last two weeks. Read on for more specifics on what’s happening in different areas across the state.  

Northwest Iowa

Leah Ten Napel (Region 1): “Like much of the state, planting in NW Iowa has been delayed by several substantial rainfall events. We have received 5-8 inches of rainfall since planting began around April 10.  Results from the spring subsoil moisture samples show that most sites are above the average amount of available moisture in the top 5 feet of the soil profile. Several sites are near or at field capacity. To learn more about the results from this year’s moisture samples visit this page. Many pastures that have been struggling due to lack of rainfall are turning a corner and greening up nicely. Alfalfa stands are coming up strong, and little pest activity has been reported at this time in this corner of the state. Some early planted corn and soybeans are starting to emerge and stands look healthy.”

Northeast Iowa

Terry Basol (Region 4): “The last couple of weeks have been a mixed bag for planting progress for NC/NE Iowa. For most of the week of April 22, weather and soil conditions were conducive for getting corn acres planted and for some, soybeans as well. For last week (week of April  29), wheels were abruptly stopped due to precipitation events throughout the week. According to the Iowa Mesonet, the NE Iowa Research and Demonstration Farm at Nashua has received 2.57 inches of rain from April 21 through May 4. The earliest planted corn has started to emerge and is in the VE – V1 stage. According to the National Agricultural Statistics Service (NASS) as of May 6, 55 and 32 percent of the acres have been planted to corn in NC and NE Iowa, respectively. For soybeans, 21 and 30 percent of the acres have been planted in NC and NE Iowa, respectively. Here’s hoping the next couple of weeks brings us favorable planting conditions for Iowa’s farmers.”  

Josh Michel (Region 5): “Over the past two weeks, most of NE Iowa has received anywhere from 1 to 3 inches of rainfall. While the rainfall has caused some short-term planting delays in some areas, it has helped improve some of the prolonged moisture stress as indicated by latest U.S. Drought Monitor. Overall, most of the region has been able to get some planting completed, but planting conditions continue to be highly variable according to soil type and rainfall amounts. Across the region, I’d estimate that 90 to 95% of the oats have been planted, while approximately 40% and 30% of the corn and soybeans have been planted respectively. Earlier planted corn fields are quickly approaching VE-V1, while early planted soybean cotyledons are just beginning to break through the soil surface. Alfalfa fields and pastures continue to green up in response to the recent rainfall and warming temperatures. Farmers should continue to scout for alfalfa weevils. I’ve seen several fields with early alfalfa weevil instars starting to become active. Other recent field calls have centered around cover crop termination, forage management, weed ID and management, and corn rootworm management.”

Southwest Iowa

Aaron Saeugling (Region 10): “Planting progress has stopped for the last week or so due to needed rainfall. Locations in Ringgold, Union, Adams, and SE Cass counties got heavy rainfall, and the saturated soils will take days to dry out. It is hard to gauge planting progress as some areas are well over 50% planted and other areas are just getting a start. Herbicide applications are behind where we need to be for the size of the weeds and acres of crop planted. Forage and pastures conditions are in decent shape and have done well with the added moisture.  Cows are going to pasture. Alfalfa insect pressure is high for both alfalfa weevil and pea aphids. I encourage alfalfa producers to sweep fields and apply insecticides when needed. It looks like more rainfall on the way as of today, May 6. Topsoil moisture has recharged, and a few cases is a bit excessive. It is too early to make planting changes yet, so just stay the course at this point and be patient.”

East Central, Southeast, and South-Central Iowa

Rebecca Vittetoe (Region 8): “Field activity has been limited the last week to 10 days with the wet conditions. Rainfall totals have ranged anywhere from over 1 inch to 5 plus inches in areas. The heavier rainfall totals were found in Keokuk and Washington counties. Planting progress is quite variable across my region, but some of the first planted corn and soybeans have emerged. If you have emerged fields, take time to scout and check stands. Also, looking at significant black cutworm flights in this part of the state, start scouting for cutworms next week. Alfalfa weevils have been the hot topic, especially in my southern counties. If you haven’t scouted your fields, I encourage you to do so. Many fields have been at threshold to spray, and we are getting to peak larvae feeding in my southern counties looking at growing degree days. If you do spray, double check the pre-harvest interval on the product and I encourage to re-scout fields 3-5 days after spraying. I’ve had a few reports of applications not providing the expected control. If you notice that, please let us know. We are looking to see if it might be due to resistance (especially if a pyrethroid product was used), related to the application method, or a combination of the two. Other recent questions have been on planting and the wetter conditions, concerns about nitrogen loss, herbicide applications, herbicide drift, weed identification, and seeding forages.”

Virgil Schmitt (Region 9): “Rainfall during the last two weeks in the counties I cover generally ranged from 1 to 5 inches, with larger amounts to the south and smaller amounts to the north. Corn planting is about one-third complete in my southern counties and about 50% complete in my northern counties. Some early planted corn is at V1 and looks good. Soybean planting is about 25% complete in my southern counties and 40% complete in my norther counties. Some early planted soybeans are at VE. First emerging soybeans in an area and soybeans planted near alfalfa should be monitored for bean leaf beetle (BLB) activity. In general, if the seed carried an insecticide seed treatment, BLB should be well managed, but those fields should still be monitored. A great deal of spraying for alfalfa weevils occurred over the last two weeks, especially south of Highway 30. So far, alfalfa weevil numbers currently are generally lower north of Highway 30. Cereal rye is heading out and you can find an occasional orchard grass plant head emerging. Phone calls, emails, and field visits last two weeks mostly involved alfalfa weevils, forage seeding, and weed identification and management.”

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