FUNGICIDES
Fungicides are classified based on their mode of action, which determines how they control fungal diseases. Below is a breakdown of different types, along with examples and the fungi they control in Texas turfgrass, trees, and shrubs.
Types of Fungicides by Mode of Action
Contact Fungicides (Protectants)
- Mode of Action: Stays on the surface of the plant, preventing infection by creating a protective barrier.
- Examples:
- Chlorothalonil (Daconil, Bravo) – Controls brown patch, leaf spot, anthracnose.
- Mancozeb (Fore, Dithane, Protect T/O) – Effective against dollar spot, rust, and leaf spots.
- Common Uses: Preventative treatments for turf, trees, and shrubs.
Systemic Fungicides (Curative)
- Mode of Action: Absorbed by the plant and moves within tissues, treating existing infections and preventing new ones.
- Examples:
- Propiconazole (Banner MAXX, Honor Guard) – Controls brown patch, dollar spot, anthracnose in turf and trees.
- Azoxystrobin (Heritage, Strobe) – Broad-spectrum, controls brown patch, take-all root rot, and rusts.
- Common Uses: Treats active fungal infections and provides long-term protection.
Penetrant Fungicides (Localized Systemic)
- Mode of Action: Absorbs into the plant but does not move far from the point of application.
- Examples:
- Fluoxastrobin (Disarm) – Used for fairy ring, brown patch, and leaf spot in turf.
- Triadimefon (Bayleton) – Effective against rust, dollar spot, and powdery mildew.
- Common Uses: Spot treatment for turf and shrubs.
Multi-Site Fungicides
- Mode of Action: Targets multiple fungal processes, making resistance less likely.
- Examples:
- Chlorothalonil (Daconil, Echo) – Prevents leaf spot, anthracnose, and rust.
- Mancozeb (Fore, Protect T/O) – Used for general disease prevention in ornamentals and turf.
- Common Uses: Broad-spectrum prevention in trees and shrubs.
Common Turfgrass Diseases in Texas & Recommended Fungicides
| Disease | Symptoms | Fungicides (Examples) |
|---|---|---|
| Brown Patch | Circular brown patches, leaf blight | Azoxystrobin (Heritage), Propiconazole (Banner MAXX) |
| Dollar Spot | Small straw-colored spots, fine webbing | Fluoxastrobin (Disarm), Triadimefon (Bayleton) |
| Take-All Root Rot | Yellowing, thinning, weak roots | Azoxystrobin (Heritage), Propiconazole (Banner MAXX) |
| Fairy Ring | Dark green rings, mushrooms | Fluoxastrobin (Disarm), Azoxystrobin (Heritage) |
| Gray Leaf Spot | Gray lesions on blades, leaf wilting | Chlorothalonil (Daconil), Mancozeb (Fore) |
Common Tree & Shrub Diseases in Texas & Recommended Fungicides
| Disease | Affected Plants | Fungicides (Examples) |
|---|---|---|
| Anthracnose | Oaks, sycamores, maples | Propiconazole (Banner MAXX), Chlorothalonil (Daconil) |
| Powdery Mildew | Crape myrtles, roses | Myclobutanil (Eagle), Triadimefon (Bayleton) |
| Rusts | Cedar, juniper, hawthorn | Mancozeb (Fore), Propiconazole (Banner MAXX) |
| Fire Blight | Pears, apples, photinia | Copper-based fungicides, Streptomycin (antibiotic for severe cases) |
| Leaf Spot | Boxwood, photinia, elms | Chlorothalonil (Daconil), Mancozeb (Fore) |
Key Takeaways
- Preventative applications are the best way to manage fungal issues.
- Rotation of fungicides is necessary to prevent resistance (especially with systemic fungicides).
- Environmental factors like moisture, temperature, and airflow significantly impact disease development.
Need Help Choosing the Right Fungicide?
For expert advice on identifying plant diseases and selecting the right fungicide, contact us:
📍 BES-TEX Supply 4512 Adobe Dr., San Angelo, TX 76903
📞 325.653.1300