Soybean Cyst Nematode is an extremely important, yield limiting pathogen of soybeans in Illinois, reducing yields an average of 1-3% across the state. As I have written in earlier posts, sampling your fields every 3-5 years to assess SCN levels and HG types is the first step in managing this issue. The best time to sample for SCN is after harvest in the Fall, and this can easily be added onto any samples you gather for soil nutrient testing. …
Remember that game of telephone we played as kids? One person says something in to the ear of another and after passing through 10 people or so the starting message, “I like peanut butter” ends up as, “John licks turtles.” Sometimes that can happen with information pertaining to plant diseases. Lately there have been some interesting things said about tar spot on corn in the community. To help clarify, and set the record straight, I published an article on my blog,…
Tarspot in corn continues to be the hot topic in our field crops this season. I put together a brief update on what we know based on this seasons observations, which can be found by clicking this link.…
Hybrid resistance is a key component for managing many plant pathogens. To access a new sheet on hybrid response to tar spot in corn click the following link: Corn Hybrid Response to Tar Spotfin.docx.
We are currently rating multiple variety trials in affected areas across states to generate more hybrid-specific data. More information will be available soon.…
Tar spot is a relatively new disease in corn. It was first described in Illinois and Indiana in 2015, and was first located near DeKalb. Tar spot has been detected to some degree in Northern Illinois each year since. However, typically infections are sparse and the disease does not come in until later in the season. Consequently, yield loss due to this disease has been minimal, and the disease mostly considered an oddity.
However, in parts of Latin America,…
Physoderma brown spot and node rot is a disease that has been increasing in incidence in the Midwest over the past 5-10 years. We observed this disease frequently during scouting trips throughout the state conducted in late July. Recently, we have been receiving more reports of this disease and questions pertaining to it’s impact on the crop and management. I recently wrote an article on this disease and management recommendations on the Illinois Field Crop Disease Blog. …
Many people have asked about the need to make a fungicide application for frogeye leaf spot on soybeans this season. I have posted a new article on the Illinois Field Crop Disease Blog which reviews this pathogen, how it works, and some new tools that may help you with these important decisions. Find the article by clicking here.…
This week there has been a slight uptick in the amount of foliar disease reports in corn, likely as many people are actively scouting prior to making a fungicide application decision. The most common disease, as you may expect is Grey leaf spot. This disease is present to varying degrees in most fields. No big surprise there.
We have seen and received several reports and samples of Diplodia leaf streak. This disease can be caused by two different species of Diplodia,…
Today we received reports of Tar spot appearing in corn grown in Illinois. We are currently studying tar spot of corn in the United States, and are requesting that any CCA, producer, or ag professional that encounters this disease, even if outside of Illinois, please send samples to Diane Plewa at the University of Illinois Plant Diagnostic Clinic.
S-417 Turner Hall, 1102 S.Goodwin Ave.
Urbana, IL 61801
Phone: 217-333-0519
Email: plantclinic@illinois.edu
Please note “Tar spot study”…
We are at that time in the season where many people will be making final decisions regarding fungicide applications in soybeans and corn. I wrote an article with tips and other items to consider when making fungicide decisions and on farm trials on the Illinois Field Crop Disease Blog, which can be found by clicking HERE. …