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:

  1. Scout in regular intervals
  2. Identify the pest
  3. Understand its life cycle
  4. Understand the causes
  5. Determine what prevention can be taken in the future
  6. Develop a plan for treatment and eradication
  7. Always follow the manufacturer's label directions when applying chemicals
  8. 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)