Integrated Crop Management News

Links to these articles are strongly encouraged. Articles may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If articles are used in any other manner, permission from the author is required.

Fall is the Perfect Time to Collect Soil Samples for SCN

October 7, 2021

The soybean cyst nematode (SCN) is a major yield-reducing pathogen of soybeans throughout Iowa and many other states. SCN-resistant soybean varieties have been used for decades to produce profitable yields and keep SCN numbers in check, but most resistant varieties have lost much of their effectiveness. Also, SCN reproduction in fields where soybeans were grown likely was much greater than normal in 2021 due to hot, dry weather. Collecting soil samples in the fall is advised to determine the SCN situation in fields. This article outlines guidelines for sampling fields for SCN, gives information on where to send SCN soil samples, and provides guidance on managing fields that are infested with SCN. 

Managing for 2022 Volunteer Corn Potential

September 14, 2021

The derecho left many Iowa farmers with significant volunteer corn this growing season, and unfortunately some may be facing a similar situation for 2022 after late August storms flattened fields.

Management of Flood-submerged Grain

September 7, 2021

In a sudden turn of weather events, there have been several severe storms in the northeast and east central crop reporting districts of Iowa. These storms have created the potential for grain quality problems; of the most immediate need for action are those corn and soybean fields that have been flooded above the grain level. Fields with lodging will have more grain susceptible to flooding.

Fall Armyworm is a 2021 Late-Season Pest

September 2, 2021

Fall armyworm is native to tropical regions in the western hemisphere. It can only successfully overwinter in the southern US (Texas and Florida), but the adults are strong flyers and capable of long-distance migration to northern states. Multiple migration events are possible each summer, and adults can be found in Iowa from June to August. This year, they are more abundant in the Midwest than usual and are causing late-season issues. As the common name suggests, larvae can still be active in October. Droughty conditions favor their development.

Yellow soybean too early this season?

August 12, 2021

Since early August Iowa farmers have been reporting soybean fields or parts of fields with yellow or greenish-yellow leaves in the upper canopy which resemble early senescence and sometimes nitrogen (N) deficiency symptoms. The soybean growth stage is mainly R4 to R5. Several factors can cause these symptoms. Rainfall has been extremely variable this season in Iowa, with severe drought still persisting in some areas of the state. Yet, areas in southern and southeast Iowa have experienced normal to excessive rainfall.

Twospotted spider mite scouting reminders

July 28, 2021
Two twospotted spider mites on a soybean leaf

Twospotted spider mites have been spotted in fields across much of Iowa already this summer, as much of Iowa is in moderate or severe drought (D1-D2, US Drought Monitor). I encourage you to scout for twospotted spider mites in crops. Twospotted spider mites can increase whenever temperatures are greater than 85°F, humidity is less than 90 percent, and moisture levels are low.

Tips for Late Summer Establishment of Forages

July 21, 2021

Mother Nature doesn’t always cooperate in the spring during the window for seeding forages. Thus, spring seeding may not have happened or stand establishment may be less than desired. Late summer provides an opportunity to establish forages or interseed into poor stands, assuming moisture is available. The recent rains may have some thinking about this, so below are some tips to consider helping a late summer seeding of forages be successful.   

Plan now

Considerations when Overseeding Cover Crops

July 13, 2021

In the last decade, cover crops have grown in both interest and acres, yet there is still room for more adoption across Iowa and the region. It is obvious that cover crops require more management though and with that management there will undoubtedly be challenges. In just a few weeks the cycle for cover crop establishment, growth and termination will begin.

Nitrogen Deficient Soybean with Excess Soil Moisture

July 13, 2021

Rainfall has been extremely variable this season in Iowa. There has been severe drought in many areas of Iowa. In contrast, rainfall has been excessive in some areas of southeast and southern Iowa. Soybean with poor growth with pale green or yellowish color has been observed in low-laying fields or field depressions with poor drainage and frequent waterlogged soils since May.