Overview of 2025 Submissions

In 2025, the MU Plant Diagnostic Clinic (MU-PDC) processed 522 physical samples and 259 digital samples. The peak period for submissions occurred during late summer, specifically in August, which accounted for 25.45% of the entire year's volume. The clinic continues to serve a diverse clients base across Missouri and beyond. The primary sample sources for 2025 were:

• Nonextension noncommercial: 281 samples (42.32%)
• Nonextension commercial: 219 samples (32.98%)
• Extension noncommercial: 92 samples (13.86%)
• Extension commercial: 72 samples (10.84%)

Sample Categories and Crop Distribution

Figure 1 Distribution of samples submitted for disease diagnosis by sample type.

Field Crops remained the dominant category for diagnostic services in 2025, followed by various ornamental and fruit categories:

1. Field Crops: 221 samples (33.28%)
2. Woody ornamental - Deciduous: 159 samples (23.95%)
3. Small Fruit: 68 samples (10.24%)
4. Vegetables: 59 samples (8.89%)
5. Woody ornamental - Evergreen: 55 samples (8.28%)

Field Crop Breakdown

Figure 2 Sample number of four major field crops submitted to MU PDC in 2025.

Within the Field Crops category, four major crops compose the bulk of the submissions:

• Soybean: 130 samples
• Corn: 42 samples
• Wheat: 14 samples
• Industrial Hemp: 14 samples

Diagnostic Highlights and Disease Trends

Soybean

Soybean submissions peaked dramatically in August with 62 samples. While early-season growth faced typical challenges from Phytophthora crown and root rot, the late-summer surge suggests a continued trend of late-season premature decline evaluations, similar to observations in 2024. The diagnostic focus remains on complex soil-borne pathogens and environmental stress factors. The diseases identified from submitted soybean sample include Charcoal Rot, Red Crown Rot, and Sudden Death Syndrome as well as Pod and Stem Blight disease. Very few Cercospora Leaf Blight or frogeye leaf spot diseases were detected from the clinic.

Corn

Corn samples were primarily submitted in July (12) and August (19). A significant portion of these diagnoses continue to focus on emerging threats such as Corn Stunt Disease, which was a major point of concern in the previous year. The clinic maintains rapid molecular assay capabilities to confirm this disease within three business days.

Wheat

Wheat diagnostic activity was concentrated in April (4) and May (7). The clinic remains committed to monitoring viral diseases such as Wheat Streak Mosaic Virus (WSMV), Soilborne Wheat Mosaic (SBWMV), Wheat Spindle Streak Mosaic (WSSMV), Cereal Yellow Dwarf Virus (CYDV), Barley Yellow Dwarf Virus (BYDV) and High Plains Virus (HPV) to provide management recommendations for future growing seasons.

Clinical Services and Submission Guidelines

The MU-PDC is implementing improved digital sample submission systems to ensure timely and smooth service. We encourage clients to:

• Review submission guidelines on our website.
• Submit high-quality photos to digital sample submission system prior to physical shipping.
• Utilize our 7-minute instructional video for step-by-step submission help.

Contact Information

University of Missouri-Plant Diagnostic Clinic
28 Mumford Hall, Columbia, MO 65211
Phone: 573-882-3019
Email: plantclinic@missouri.edu
X (Twitter): x.com/MUplantclinic

Field Crops: Disease Highlights (2025)

The 2025 season saw a high prevalence of soil-borne pathogens in row crops, particularly in soybeans.

Table 1 Major Diseases and Issues in Field Crops (2025).