By Blake Jackson
The University of Missouri (MU) Extension will host its annual Crop and Pest Management Field Day on July 10 at Bradford Research Farm in Columbia. The event will focus on important crop disease threats including tar spot in corn and red crown rot in soybeans.
MU Extension plant pathologist Mandy Bish will present insights into these two major diseases. Tar spot, which affects corn, has been present in Missouri since 2019 and has now been confirmed in 63 counties. The disease causes small black spots on both sides of corn leaves and can lead to severe yield losses, ranging from 20 to 40 bushels per acre during high-pressure years.
Bish notes that while tar spot is becoming more common, it does not always justify fungicide use. She will offer recommendations on how to identify the disease, optimal fungicide timing, and cost-effective management strategies.
The field day will also introduce attendees to red crown rot, a new threat to Missouri soybeans confirmed for the first time in 2024. The disease survives in plant residue and thrives in warm, wet conditions. Yield losses from red crown rot can be between 15% and 70%.
To detect red crown rot, Bish recommends a “roots up and stems split” approach. This involves digging up affected soybean plants and examining their roots and split stems, which helps differentiate red crown rot from similar-looking diseases like sudden death syndrome.
Registration details for the field day will be available soon on https://extension.missouri.edu/events. MU Extension’s Kevin Bradley and Mandy Bish encourage growers, students, and ag professionals to mark their calendars for this important event.
Photo Credit: university-of-missouri
Categories: Missouri, Crops, Soybeans