Photo by Steven Clough

USDA and University of Illinois researchers are working together to understand a new disease affecting soybean in Illinois, red crown rot (RCR) causedby  Calonectria ilicicola.  Occurrence of RCR was first reported on soybean in the United States in 1972, but the disease was only recently reported on soybeans in Illinois. However, because the foliar symptoms resemble SDS (see photos above) it might have been present longer and people didn’t realize it.

Photo by Steven Clough

RCR resembles SDS but the most distinguishing sign of RCR is the reddish coloration at the base of the stem, and the possible presence of small reddish globules which are the fungal reproductive structures called perithecia (see photos above). The red discoloration darkens as plants mature.

Please assist researchers studying this new disease by helping us collect samples and letting us know approximately where samples were collected. One aspect of the analyses is to document its spread and characterize its diversity, so we need samples from many different locations across the state. Samples can be the entire plant or only the infected crown region. Individual samples can be placed in a plastic bag and kept cool until you can ship.

Please see Plant Clinic form and address below.

For more info:

U of IL Plant Clinic & USDA Soybean Red Crown Rot Free Sample Diagnosis Form   – click here to download   

Field location (GPS coordinates or landmarks—if sending multiple samples, please place one sample per plastic bag and place a piece of paper with this info in each sample bag, or write it on each bag with a marker):

Town/Township and County (and state, if not IL):


Email or Phone:

Samples should be kept cool and shipped early in the week.

Please include this form and ship to:

Plant Clinic

S-417 Turner Hall

1102 S. Goodwin Ave.

Urbana, IL 61801

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About the Author: Steven Clough

Dr. Clough is known internationally for his work on Arabidopsis transformation. His main research focus is on the use of genomics and molecular biology to explore plant-microbe and plant-pest interactions, mainly in soybean. His work improves our understanding of plant defense biology and identifies soybean genes affecting defense. Dr. Clough is a Research Geneticist at USDA-ARS in Urbana, IL and Assistant Professor in the Dept. of Crop Science at the University of Illinois at Urbana-Champaign.

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