Regional Update: May 3 to May 11, 2021

May 11, 2021 10:34 PM
Blog Post

This past week brought some much needed and welcomed rain across the state. Planting is getting on the downhill slide with corn planting about 86% complete and soybean planting about 67% complete across the state according to the May 10 USDA-NASS Crops Progress Report. Iowa State University Extension and Outreach field agronomists share reports on what they are seeing and hearing in their respective regions across the state with field conditions and planting progress.

Northwest Iowa

Joel DeJong (Region 1): “I am writing this on Tuesday morning (May 11), and the temperature reads 32o F in Le Mars. That means some low-lying areas likely saw colder temperatures than that. Emerged plants might have received some damage, but it will be a few days before we] will know for certain. However, I suspect frost damage will be limited (I hope!). Corn has been emerging during the last week but less than half of the corn is up right now. I know a few bean fields that have emerged, but I have not been in any of them. We did see some leaf tissue damage on emerged corn from cold mornings last week, maybe more will be seen later this week. Emergence under these cool conditions does not seem to be very uniform in many fields, but stands are improving. Rainfall was widespread, with amounts reported starting at 0.3 inch to some reporting over an inch. Much needed as some seeds have been laying in dry soil. More would be welcome. Almost all the corn is planted, and l would estimate about 80% of the beans have been planted. Bring on warmer weather!"

The coolder nighttime temperatures caused some tissue damage like this on emerged corn seedlings. Photo courtesy of Joel DeJong.

Paul Kassel (Region 2): “Corn and soybean planting is mostly complete across much of my area. The main stories this week have been the frost and the lack of rainfall. A very welcome rain occurred over much the area on May 8. However, there are areas in Dickinson, Emmet, Clay, northern Kossuth and Winnebago counties which received from 0.1 to 0.2 inches. Most of the rest of my area received around 0.5 to 0.8 inch on May 8. Frost has been the other big concern this week, especially for emerged soybean plants. Temperatures dipped into the upper 20’s on May 11. Farmers and agronomists are encouraged to stake out a few feet of a soybean row and then evaluate that same area for frost damage to the soybean plants in the next few days. Frost damage to the soybean crop will appear as black and shriveled plants."

The radicle has emerged on these May 5 planted soybeans. Photo courtesy of Paul Kassel.

Northeast Iowa

Josh Michel (Region 5): “Most of the region received 0.5 to 1 inch of precipitation early in the week, with a few isolated areas receiving up to 1.5 inches. While this delayed some farmers from finishing up planting, it was welcomed by many areas that haven’t seen any measureable precipitation in over 30 days. Around 70 to 75% of the corn acres are planted, and soybeans are around 60 to 65% planted. Oat stands continue to come up and are looking good. Although the rainfall will help, alfalfa growth is slower with the cooler temperatures. There have been some minor and isolated reports of frost damage to alfalfa with recent low temperatures hovering around freezing. Pastures continue to do well with cool temperatures and timely precipitation. Recent field calls and questions have included: cover crop termination, weed identification and management, pasture and alfalfa management, corn rootworm management, and concerns about frost damage to crops.”

Seeing some minor and isolated frost damge in some alfalfa fields. Photo courtesy of Josh Michel.

East Central, South Central, and Southeast Iowa

Rebecca Vittetoe (Region 8): “Corn planting is getting close to wrapping up, and soybean planting is about 60 to 70% complete. The first planted corn and soybeans have emerged. Take time to scout and evaluate stands as I’ve seen and have also heard reports about uneven emergence issues with the drier soil conditions at the start of planting. While we were fortunate to catch some rain last Monday (May 3), we caught some more over the weekend, bringing the weekly rainfall totals across my area to 0.75 to 3 plus inches. Pasture and hayfields look pretty good and seem to finally be getting some decent growth on them. I've been able to find both alfalfa weevil adults and larvae as well as some aphids when sweeping hayfields fields. Just a reminder to take time to scout your pastures and hayfields too! Weed identification, herbicides and herbicide programs, stand evaluations, and cutworm dates were the common questions I received over the last week.”

Seeing a variety of insect pests in some alfalfa fields including aphids and alfalfa weevils (adults and larvae). Photo courtesy of Rebecca Vittetoe.

Virgil Schmitt (Region 9): “Rainfall last week in the counties I cover was generally 1.5 to 4.0 inches of rain, with the heaviest amounts along and between Highways 34 and 92. Most of the rain was Saturday (May 8) night. In general, temperatures last week in the counties I cover were 1 to 3 degrees below normal. Corn planting is about 85% complete and soybean planting is about 60% complete. Herbicide product and rate selection were the main topics of conversation last week. Orchard grass and smooth bromegrass are starting to head out."

Rainfall totals across the state from May 3 to May 9, 2021. Source:

Josh Michel (Region 11): “The phrase, ‘when it rains, it pours’ could be used to accurately describe most of region recently as two storm systems delivered anywhere from 3 up to 4.5 inches of precipitation this last week. As a result, planting has come to standstill with roughly 80 to 85% of the corn acres planted, and soybeans are around 50 to 55% planted. Early planted corn and soybeans are just starting to emerge. The earliest planted corn is at V1. Oats are around 70% emerged and are looking good so far. Pastures and alfalfa continue to grow well with cooler temperatures and recent rainfall. Recent field calls and questions have centered on delayed cover crop termination, weed identification and control, as well as pasture, alfalfa and small grains management.” 

Take time to scout emerged fields and evaluate stands. Photo courtesy of Josh Michel.

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...