Between severe drought conditions in the western half of Iowa and a derecho that tore through the center in August, fields were hit with difficult weather in 2020. Weather plays a part in your decision-making process of selecting corn hybrids and soybean varieties to plant in 2021.

Severe lodging left more ears and kernels on the ground this fall, setting the stage for volunteer corn problems in those fields next year. “Selecting a soybean variety that fits your volunteer corn control program is very important,” says Mike Witt, Iowa State University Extension agronomist in west-central Iowa.

An article by ISU agronomists and a video show examples and ideas for dealing with downed corn and volunteer corn management for 2021. To read the article and view the video, click on Management of volunteer corn in fields affected from derecho and Video: Management of volunteer corn.

Difficult weather conditions and lodged corn aren’t the only factors to consider when making decisions on which corn hybrids and bean varieties to plant in 2021. Two other articles explain the aspects of corn hybrid and soybean variety selection that are critical regardless of the previous cropping year. ISU Extension agronomist Mark Licht wrote these two articles, Corn Hybrid Selection and Soybean Variety Selection.

Soil moisture supplies this fall are variable across Iowa. Farmers in the driest areas may be more apt to decide to plant a corn hybrid or bean variety that has more potential for drought tolerance. Soil moisture can change over winter, but understanding that 2021 is starting at a deficit or a surplus helps with those decisions. Drought tolerance might be more important in 2021 than in previous years.

Herbicide key decision

“Also consider herbicide trait packages for 2021, especially for soybeans,” Witt says. There could be an increase of volunteer corn in fields that could alter plans for weed control. Also, recent court cases involving dicamba and other labeled herbicides make it imperative you choose the correct seed traits for your fields.

Rotating herbicides according to site and modes of action can be more easily managed in 2021 with more options available. But these options can carry risks for environmental contamination if not placed properly. Traits and technology can help farmers be more efficient, but they can also be harmful and more costly if used incorrectly.

Corn rootworm resistance is another issue that’s been creeping up on some farmers. There is an increase in resistance of rootworms to the control traits offered in specific corn hybrids. These traits and proteins will eventually develop resistances and are not “bullet proof” methods of controlling corn rootworm as some people would like to believe.

A properly integrated management system of crop and trait rotations needs to be used if seeing resistance issues in your fields. Corn-on-corn fields with multiple years of the same trait packages being used in high rootworm pressure areas are particularly prone to failures. Thus, 2021 is a good year to get in front of these insect issues by rotating crops, switching traits or adding different insecticides to your mix. A little bit of management goes a long way in preventing resistance.

“Knowing where your fields stand after 2020 and making a few small changes in management, or hybrid and variety selections will help reduce the yield-robbing potential this year gave us,” Witt says. “If 2020 taught farmers anything, it is to expect the unexpected in 2021 and prepare accordingly.”