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.

Variable Overwintering Success for Bean Leaf Beetles this Year

April 26, 2023

Bean leaf beetle adults (Photo 1) are susceptible to cold weather, and most will die if exposed to air temperatures below 14°F. However, they avoid harsh temperatures by burrowing under plant debris and loose soil. Each spring, adult beetles emerge from their overwintering habitat and migrate to available hosts, such as alfalfa, tick trefoil, and various clovers. As the season progresses, bean leaf beetles move to preferred hosts, like soybean.

Establishing a New Stand of Alfalfa

April 14, 2023
corregated roller in action.

Spring has arrived and many fields are full of activity. April is a great time to seed alfalfa whenever the soil is fit. Shallow-seeded forages will germinate and grow very quickly with adequate soil moisture and just a few warm days. The key to getting a great alfalfa stand is proper soil preparation and timing of the seeding.

Seedcorn Maggot Activity Beginning in Southern Iowa

April 10, 2023
Seedcorn maggot on soybeans.

Seedcorn maggot larvae feed on germinating seeds or seedlings of corn and soybean (Photo 1). Feeding can delay development or kill the plant, and plant injury is especially prevalent during cool, wet springs when plants grow slowly. Even with variable weather so far this spring, seedcorn maggot development is on track with previous years. Forecasted temperatures suggest that seedcorn maggot will likely develop quickly in the next few weeks.

Scouting for Winter Injury in Alfalfa Fields

April 7, 2023
winterkill in alfalfa.

While row crops are generally the focus of attention this time of year, spring is a great time to scout for winter injury in alfalfa fields and assess stand health. This is especially true if stands did not have adequate snow cover or were covered by sheets of ice during the winter. Several other factors may contribute to alfalfa winter injury, including soil moisture, 4-inch soil temperatures, and other stresses like soil fertility, stubble height, as well as the age of the stand.

Check FieldWatch® Before Pesticide Applications

March 31, 2023

Prepare for a safe pesticide application season by checking the FieldWatch® registry before making pesticide applications. The FieldWatch® registry provides easy-to-use, accurate, and secure online tools to enhance communications and awareness between crop producers, beekeepers, and pesticide applicators. FieldWatch® features a voluntary mapping tool through Google Maps™ that shows pesticide applicators the locations of registered sensitive crops and beehives so they can make informed decisions regarding pesticide applications.

Washing Work Clothes After Working with Pesticides

March 30, 2023
Internal view of a washing machine, by nexusseven/

Pesticide residues can be carried on your clothing even if you wear personal protective equipment (PPE) over your own work clothes. Therefore, it is important to properly clean your clothes after working with and around pesticides. Many pesticide labels provide limited instructions for cleaning work clothes. In situations where no instructions are provided, follow these guidelines for washing contaminated clothing. 

Newly Updated Phosphorus and Potassium Guidelines

February 28, 2023
Relationships between soil-test P and relative corn and soybean grain yield responses.

Guidelines for soil-test phosphorus (P) and potassium (K) interpretations and application rates were last updated in 2013. Since then, significant field research was conducted to assure that nutrient management guidelines are kept current. The new response data, increased crop yield levels in Iowa, and better awareness of usually large spatial soil-test variability in production fields indicated a need for adjusting the boundaries of soil-test interpretation categories and suggested nutrient application rates.

More soybean varieties with Peking SCN resistance for 2023, but more needed

November 22, 2022
Yellowing field of soybeans.

A list of SCN-resistant soybean varieties for use in Iowa is compiled and made available every fall as ISU Extension publication PM 1649. The updated list recently has been made available online. Overall there are fewer SCN-resistant soybean varieties than in past years, but there are varieties from more brands (27) in this year’s publication. Most importantly, there are 47 varieties with Peking SCN resistance in the 2022 list, which is 13 more than were in the list in 2021. Soybean varieties with Peking SCN resistance are highly valued because they limit reproduction of Iowa SCN populations much more than varieties with the common PI 88788 resistance.

Managing Burcucumber in Corn and Soybean

November 4, 2022
Burcucumber infestation in a corn field in Iowa.

With harvest winding down, one weed that made harvest more frustrating for some is burcucumber. Consequently, there have been many questions on how to better manage this weed to prevent those frustrations.