There were fewer insect challenges than usual for Illinois farmers in 2020, according to WinField United agronomist Jason Haegele. He says insects that are typically problematic for Illinois farmers, including Japanese beetles, were not as prevalent in fields last season. Corn rootworm was also more manageable in 2020, likely due to increased use of insect traits and recent wet springs that have reduced larvae populations.
One common insect pest last year was the bean leaf beetle, which was a late-season problem for some farmers in central and northern Illinois. Although insect populations were low in 2020, Haegele says that’s not necessarily indicative of what they’ll be like in 2021. In-season scouting to assess insect pressure will be key for management success next season.
Haegele says there were a fair amount of corn diseases in Illinois fields in 2020. Gray leaf spot was common throughout the state. In northern Illinois tar spot was prevalent, while southern parts of the state saw a fair amount of Southern rust. Foliar diseases were limited in soybeans in 2020, but soil-borne pathogens, including sudden death syndrome, brown stem rot and red crown rot did appear in some fields. Haegele says the trend toward earlier planting when soil conditions are wet and cool makes soybeans more susceptible to these soil-borne diseases.
Soybean cyst nematode (SCN) is another pest that Illinois farmers should be keeping an eye out for. Haegele suggests soil sampling to identify if nematodes exist in fields and if they do, to what extent. He says there is evidence to suggest that SCN resistance in soybeans isn’t as effective as it used to be, so farmers may need to consider different management strategies, including crop rotation, for control.
Haegele says farmers in Illinois continued to realize the benefits of foliar fungicide applications in 2020, especially to manage foliar diseases in corn. He says it’s difficult to control the soybean soil-borne diseases in-season, but farmers can choose more tolerant varieties and effective seed treatments to help protect against them. As farmers plan their disease-control strategies for 2021, Haegele urges them to review the hybrids they’ve chosen to determine their expected response to a fungicide application. Then, farmers can develop plans for those applications.