Plant Disease
Fungi and plant diseases pose a threat to many areas of the horticultural industry. From nurseries, greenhouses, and homeowners to landscapers, arborists, and lawn care professionals—all are potentially affected by anomalies and fungal diseases in plants. Plant diseases are devastating to investments and cost valuable time, labor, and money.
To combat this potential burden, AM Leonard has put together a quick guide for plant disease and fungus management—a helpful matrix that matches specific plant diseases with the most effective products available. We’ve also included the listed brand’s active ingredient and method for your reference.
To start, always practice strong IPM (Integrated Pest Management) fundamentals, which include, but are not limited to, the following:
- Scout in regular intervals
- Identify the pest
- Understand its life cycle
- Understand the causes
- Determine what prevention can be taken in the future
- Develop a plan for treatment and eradication
- Always follow the manufacturer's label directions when applying chemicals
- Never apply chemicals just to apply them
Below you’ll find our matrix of common problems along with treatments for the Midwest, Northeast, South, and West regions*. Please note that timing, disease, and method may vary by region. Reference your local county extension service for more information.
Legend |
Method (Code) |
Foliar Spray |
(FS) |
Broadcast |
(B) |
Drench / Chemigation |
(D), (CH) |
Incorporate / Topdress |
(I), (T) |
*There are many more diseases controlled than this list illustrates. Please refer to manufacturers label for direct guidance.
OMRI – Listed ^^ / Biological
Fungus/Disease/Anomalies | Brand** | Active Ingredient | Method |
Anthracnose | Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) | |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D),(FS) | |
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) | |
Leaf Spot | Biophos Pro | Dipotassium Phosphate | (D),(FS) |
Dipotassium Phosphonate | |||
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Pythium | Biophos Pro | Dipotassium Phosphate | (D),(FS) |
Dipotassium Phosphonate | |||
Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) | |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D),(FS) | |
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) | |
Phytophthera | Biophos Pro | Dipotassium Phosphate | (D),(FS) |
Dipotassium Phosphonate | |||
Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) | |
Botrytis | Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D),(FS) |
Biophos Pro | Dipotassium Phosphate | (D),(FS) | |
Dipotassium Phosphonate | |||
Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) | |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D),(FS) | Chlorosel Pro 720 | Chlorothalonil | (FS)(CD) |
Alternaria | Biophos Pro | Dipotassium Phosphate | (D),(FS) |
Dipotassium Phosphonate | (D),(FS) | ||
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) | |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D),(FS) | |
Blight | Eagle 20EW | Myclobutanil | (FS),(CH) |
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Biophos Pro | Dipotassium Phosphate | (D),(FS) | |
Dipotassium Phosphonate | |||
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) | |
Rust | Eagle20EW | Myclobutanil | (FS),(CH) |
Chlorosel Pro 720 | Chlorothalonil | ||
Downey Mildew | Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) |
Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) | |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D),(FS) | |
Powdery Mildew | Eagle 20EW | Myclobutanil | (FS),(CH) |
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) | |
Rhizoctonia | Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D) | |
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Stem Canker | Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) |
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) | |
Scab | Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Dollar Spot | Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Brown Patch | Eagle 20EW | Myclobutanil | (FS),(CH) |
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Fusarium | Actino-Iron ^^ | (Streptomyces Lydicus WYEC 108) | (I),(T) |
Actinovate SP ^^ | (Streptomyces Lydicus WYEC 108) | (D) | |
Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) | |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Black Spot | Chlorosel Pro 720 | Chlorothalonil | (FS),(CH) |
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) | |
Eagle 20EW | Myclobutanil | (FS),(CH) | |
Root Rot | |||
Agri-Fos Sustemic Fungicide | Mono/Dipotassium | (FS),(I)(D) |