Corn
Iowa leads the nation in corn production. Find the latest research-based information for corn production in Iowa as well as the basic agronomics of corn production and corn growth and development.
Corn Tools and Resources
- Corn and Soybean Field Guide
- Corn Growth and Development
- Corn Staging
- Key Corn Growth Stages
- Guide to Iowa Corn Planting
- Forecast and Assessment of Cropping sysTemS
- Corn Drydown Calculator
- Corn Nitrogen Rate Calculator
- Iowa Crop Performance Tests - Corn
- Iowa Grain Quality Initiative
- Corn Content Index
Iowa leads the nation in corn production. Find the latest research-based information for corn production in Iowa as well as the basic agronomics of corn production and corn growth and development.
Timely Insights on Corn
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May 14, 2025Content Author
Each year brings fresh concerns related to herbicide performance and the weather. We can’t control the weather, and we are often at the mercy of wind, temperature, and moisture whether there is too much, too little, or ideally, just right. A recurring concern this spring has been dry weather and how it impacts herbicides.
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May 13, 2025Content Author
The week of May 4 saw a bustling of field activity across the state. Planting is winding down in many areas across the state, and the farthest along corn is between V2 to V3 and the farthest along soybeans are VC. Stand concerns due to soil crusting and anhydrous ammonia burn emerged this last week, particuarlly in parts of central and NC Iowa. As well as did concerns for weed control either due to weeds coming through PRE herbicides already applied or lack of moisture to activate PREs recently applied or that are going on now. ISU Extension and Outreach field agronomists share more specific updates about what is happening in the regions they cover below.
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May 6, 2025Content Author
Fieldwork and planting were limited in some areas of the state over the past week due to wet weather and unsuitable field conditions. Nearly 50% of the corn and about 40% of the soybean crop have been planted statewide. Earlier-planted corn and soybean fields have emerged. So far, aside from weeds, minimal pest pressure or other major issues have been noted in fields across the state. ISU Extension and Outreach field agronomists provide more specific updates about conditions in the regions they cover below.
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May 6, 2025Authors
Black cutworm (BCW) is a migratory pest that arrives in Iowa each spring. We monitor moth activity around the state with our Iowa Moth Trapping Network, and there has been quite a bit of BCW moth activity this spring. The female BCW moths lay eggs in and near crop fields. The eggs hatch and the larvae can feed on corn leaves or even cut corn seedlings. Larvae must attain a certain size (4th instar) to be large enough to cut corn plants, and cutting can occur until plants reach the V5 stage. We predict when BCW will big enough to cut corn plants based on growing degree day data and the occurrence of significant flights.
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May 2, 2025Content Author
Rain and wind has impeded getting fieldwork done this spring, but it looks like the weather forecast is heading for drier conditions. This will allow farmers to get the remaining corn and soybean fields planted across Iowa prior to when yield potential starts to drop off in mid-May. The latest USDA Crop Progress Report estimates that 34% of our corn is planted and 25% of the soybean crop is planted.
