Integrated Crop Management News

Farming and Conserving Pollinators in Iowa: Combining Two Great Activities in One Place

A recently published summary of over 15 years' worth of research reveals farmers can conserve pollinators at the edges and even inside corn and soybean fields. This conservation is in the form of prairie strips planted with native, perennial flowering plants. Prairie strips offer significant food and nesting habitat for pollinators

Post-Pollination Insect Pests to Look Out For

Pollination is complete for most cornfields in Iowa, but it is still important to continue scouting for insect pests that may be robbing corn yields as the season progresses. We do not recommend using foliar insecticides unless scouting determines a need to spray. Some pests are resistant to older active ingredients, such as pyrethroids, and careful identification will determine what product would be more effective. In addition, prophylactic use of insecticides will limit any benefits that natural enemies may provide. 

Japanese Beetles Ahead of Schedule in 2026

Japanese beetle development is about two weeks ahead of schedule this spring, which is not too surprising with the warm May temperatures. Japanese beetle adults begin emergence when approximately 1,030 growing degree days (GDD; base 50°F) have accumulated since January 1 and will continue emerging until 2,150 GDD have accumulated. 

2026 Stalk Borer Movement to Corn

Stalk borer is an occasional pest of corn, but it can be persistent in some fields, especially those fields near perennial grasses that serve as overwintering sites (fence rows, terraces, and waterways are typical sites). Tracking degree days is a useful way to estimate when common stalk borer larvae begin moving into cornfields from their overwintering hosts. 

2026 Black Cutworm Cutting Predictions

Black cutworm (BCW) is a migratory pest that arrives in Iowa with spring storms each year. Black cutworm moths lay eggs in and near crop fields, and larvae can feed on leaves or cut seedlings of corn, soybean, and other plants. Black cutworm infestations are unpredictable, making it essential to scout to determine whether BCW larvae are present in a field and if management is required. 

2026 Bean Leaf Beetle Overwintering Mortality

Bean leaf beetle adults are susceptible to cold weather, and most will die if exposed to air temperatures below 14°F. They avoid harsh temperatures by burrowing under plant debris and loose soil. In early spring, adult beetles migrate to available hosts, such as alfalfa, tick trefoil, and various clovers. They are strongly attracted to soybean, and adults move throughout the landscape to find soybean fields with emerging seedlings. While initial adult activity can begin before soybean emergence, peak abundance often coincides with emergence and development of early planted soybean fields, leaving those fields prone to defoliation.

Phosphorus and Potassium Management with High and Uncertain Prices This Spring

This spring began with higher and uncertain phosphorus (P) and potassium (K) fertilizer prices, with a higher increase for P fertilizers. Fortunately, corn and soybean grain prices began increasing in February and expectations are for further increases, mainly for corn (Chad Hart - Ag Market Outlook). Although many producers already applied the phosphorus (P) and potassium (K) needs for 2026 last fall, others will apply them this spring and are considering reducing planned rates due to lower expected economic benefits from fertilization. However, reducing P and K rates across all conditions is not a good management decision.

Seedcorn Maggot Already Active in 2026

Seedcorn maggots feed on germinating seeds or seedlings of both corn and soybean (Photo 1). Feeding can slow development or kill the plant, and plant injury is more prevalent during cool, wet springs when plants grow slowly. With planting right around the corner, we recommend that farmers track growing degree days, plant during the fly-free period, and avoid planting into cool, wet soils, especially in fields at high risk for injury. High-risk fields include those with a history of seedcorn maggot injury, recently tilled fields, and fields where organic matter was recently incorporated (e.g., manure or cover crops).

Alfalfa Weevil Eggs Hatching Early in 2026

Warm temperatures early in 2026 have accelerated alfalfa weevil development in Iowa. Adults have already emerged from their overwintering sites to lay eggs in alfalfa stems throughout the southern half of Iowa. 

2025 Corn Rootworm Monitoring Network Summary

2025 was the sixth year of a coordinated effort to monitor corn rootworm adults across Iowa and the fifth year of combining this effort with the Regional Corn Rootworm Monitoring Network. The Hodgson Lab received funding from the Agricultural Stewardship Technical Committee to distribute traps to volunteer cooperators across corn-growing regions in the U.S. and Canada. The 2025 regional report is published, but this article summarizes the Iowa results in greater detail.

2026 Crop Advantage Series Meetings to Be Held at 12 Locations in January

Fall is the Best Time to Sample Fields for Soybean Cyst Nematode

The soybean cyst nematode (SCN) is the most damaging pathogen of soybeans in Iowa and the entire US. The pathogen warrants more attention and management effort than often is given. SCN is easily detected and quantified from soil samples. An optimum time to collect soil samples from fields is in the fall, after the harvest of corn and soybeans is complete. This article explains how to collect and submit soil samples for SCN testing.

Soybean Cyst Nematode-resistant Soybeans Varieties for Use in Iowa in 2026 include 196 with Peking Resistance

Growing resistant soybean varieties is critical to achieving and maintaining profitable soybean yields in fields infested with the soybean cyst nematode (SCN). A list of SCN-resistant soybean varieties in maturity groups 0-3 available for use in Iowa is compiled annually by ISU personnel. This year, there are 908 SCN-resistant soybean varieties from 35 brands offered for sale by 25 companies included in the list. This article contains information about the varieties in the updated list, including their genetic sources of resistance, plus a link to the list.

Corn Harvest, Handling, Drying, and Early Storage Considerations for 2025

As fall approaches, Iowa corn farmers often experience a mix of emotions. Even without a clear picture of what this fall will bring, there are several key considerations to help prepare for the long haul of harvesting, handling, drying, and early storage of this year’s corn crop.

Fertilizer and Finance Workshop To Be Offered Aug. 27

The Humboldt County Extension Office will host a Fertilizer and Finance workshop on Wednesday, Aug. 27, from 8:30 to 10:30 a.m. at their location, 727 Sumner Ave, Humboldt.  

North Central Iowa Research Association and Iowa State University to Host Fall Field Day

Iowa State University’s Northern Research and Demonstration Farm will host its Fall Field Day on Thursday, Sept. 4.

Making Sense (Cents) of Tank-Mixing

Tank-mixing pesticides is one of the many ways farmers try to increase efficiency each year. But just because we can do something doesn’t mean we should be doing it. Does tank-mixing pesticides make sense, or rather, cents, in field crops?

Rootworm Eggs Reaching Peak Hatch in Iowa

Corn rootworm egg hatch in Iowa typically occurs from late May to the middle of June, with an average peak hatching date of June 6 in central Iowa. Development is driven by soil temperature and measured by growing degree days (GDDs).

Call for volunteers! Help us monitor for adult corn rootworms in 2025

The regional rootworm trapping network enters its sixth year in Iowa. We will be monitoring corn rootworm adults throughout Iowa to get a sense of how populations vary across the state, both in numbers and in species composition (ratio of westerns to northerns). Since this is a huge undertaking, we are asking for volunteers to monitor sticky traps this summer.