MU Plant Diagnostic Clinic 2026 Semi-Annual Report For Field Crops
PENG TIAN
COLUMBIA, MISSOURI
In the first half of 2026, the MU Plant Diagnostic Clinic (MU-PDC) processed 420 samples, and 129 sets of digital diagnostic submissions. The diagnostic services provided for these 420 samples include plant disease diagnosis (109), insect identification (5) and plant and weed identification (6). There was an increase of 113% in physical sample number and 150% in digital sample number, compared to the data of the first half of 2025.
Sample Sources and Client Demographics
Table 1 The distribution of sample sources (1/2026-6/2026).
|
Sample Source
|
Number of Samples
|
%
|
|
Nonextension noncommercial
|
263
|
62.62%
|
|
Extension noncommercial
|
48
|
11.43%
|
|
Extension commercial
|
21
|
5.00%
|
|
Nonextension commercial
|
88
|
20.95%
|
|
Total
|
420
|
100
|
Distribution of Samples by Category
Figure 1 Distribution of samples submitted for disease diagnosis by sample type (1/2026-6/2026)
Summary of Field Crop Diagnosis
Figure 2 Number of field crop samples (1/2026-6/2026)
Soybean
The clinic processed 29 soybean samples during this reporting period. The most common issues identified included herbicide injury, damping-off, and Phytophthora root and crown rot. Starting in June 2026, the MU-PDC launched a free diagnostic testing program for red crown rot and its lookalikes–including sudden death syndrome (SDS), brown stem rot, and Dectes stem borer. This initiative is supported by the United Soybean Board and the Missouri Soybean Merchandising Council, in cooperation with University of Missouri Extension.
Corn and Wheat
To date this season, no corn stunt disease has been confirmed in Missouri. In wheat, the most prevalent viral issue continues to be wheat streak mosaic virus (WSMV), which is vectored by the wheat curl mite (Aceria tosichella). WSMV is part of a destructive complex of three closely related viruses that share the same mite vector, alongside Triticum mosaic virus (TriMV) and High Plains wheat mosaic virus (HPWMV).
Submission and Clinical Improvements
To assist in providing timely results, MU-PDC has streamlined online digital submission system. We encourage all clients to take clear, well-focused photos of both the overall plant environment and close-up symptoms before shipping physical material.
Contact Information
University of Missouri-Plant Diagnostic Clinic
28 Mumford Hall, Columbia, MO 65211
Phone: 573-882-3019
Email: plantclinic@missouri.edu
PENG TIAN
UNIVERSITY OF MISSOURI