Understanding Common Fungicides: An Essential Guide
Fungicides are crucial tools in gardening and agriculture, designed primarily to prevent fungal diseases that can severely impact plants. Unlike insecticides, which target visible insects, fungicides are preventative measures aimed at stopping diseases before they become a problem. Once fungal diseases, such as leaf spots, have manifested on plants, there are no fungicides that can remove these spots. Instead, fungicides work to prevent the spread of the disease.
Types of Fungicides
Several common fungicides are widely used, each with specific applications:
1. Chlorothalonil: This is a broad-spectrum fungicide found in various products under different trade names, such as Daconil. It’s effective against many vegetable diseases, including tomato blight and plant leaf spots.
2. Mancozeb: Similar to chlorothalonil, mancozeb is used for controlling a wide range of fungal issues in vegetables and fruits.
3. Captan: Predominantly used for fruit trees, Captan helps combat rots and diseases like brown rot on peaches and black rot on apples. It's a staple in many home orchard sprays.
4. Sulfur: A biological fungicide that’s effective against numerous fruit diseases, including leaf spots and rot. It can also used in organic farming.
5. Myclobutanil, Propiconazole, Tebuconazole: These systemic fungicides are absorbed by the plant and move through its tissues. They offer extended protection and are often recommended for ornamentals.
6. Copper: Copper fungicides, such as copper sulfate, are used extensively in the pecan industry for controlling diseases affecting pecan trees.
7. Strobilurins: These are newer systemic fungicides frequently used in turf grass management. They control diseases like brown patch and dollar spot and are used to maintain healthy lawns and golf courses.
8. Botanical and Biological Options: For those interested in organic methods, sulfur is a go-to option. Neem oil, clove oil, rosemary oil, and Bacillus subtilis are also known for their antifungal properties.
Systemic vs. Contact Fungicides
Fungicides can be classified as systemic or contact. Systemic fungicides are absorbed by the plant and move within the plant to ensure more even coverage. They can offer prolonged protection, potentially from 7 to 21 days, depending on the formulation. They may also provide some curative effects if the infection is relatively recent. Contact fungicides, on the other hand, are not absorbed and generally offer protection for 7 to 14 days. They work by creating a protective coat on the plant to prevent fungus spores for growing.
Application Tips
When using fungicides, it's important to read and follow the label instructions carefully. The label will indicate which diseases the product can control, how to apply it, and any necessary safety precautions.
For optimal results and to avoid resistance, you should rotate between different classes of fungicides. Some products combine multiple active ingredients to combat resistance and broader disease spectra.
Fungicides can be applied as liquids or powders, with liquid formulations often preferred for their ease of mixing. However, if using powder, ensure it is well-dissolved before application. Always keep the spray mixture well-agitated to maintain effectiveness.
On fruits and vegetables, be mindful of withdrawal (or pre-harvest interval) periods before harvest, as most fungicides require a specific time to elapse before the treated produce can be safely consumed.
By understanding these basics and applying fungicides correctly, you can help protect your plants from fungal diseases and maintain a healthy garden.
Related Videos:
Mixing and Applying Fungicide
Spraying Fungicide
Related Resources:
Fungicides and Bactericides for Home Fruits, Vegetables, and Ornamentals (UT Redbook)
Using Organic Fungicides
Types of Fungicides
Several common fungicides are widely used, each with specific applications:
1. Chlorothalonil: This is a broad-spectrum fungicide found in various products under different trade names, such as Daconil. It’s effective against many vegetable diseases, including tomato blight and plant leaf spots.
2. Mancozeb: Similar to chlorothalonil, mancozeb is used for controlling a wide range of fungal issues in vegetables and fruits.
3. Captan: Predominantly used for fruit trees, Captan helps combat rots and diseases like brown rot on peaches and black rot on apples. It's a staple in many home orchard sprays.
4. Sulfur: A biological fungicide that’s effective against numerous fruit diseases, including leaf spots and rot. It can also used in organic farming.
5. Myclobutanil, Propiconazole, Tebuconazole: These systemic fungicides are absorbed by the plant and move through its tissues. They offer extended protection and are often recommended for ornamentals.
6. Copper: Copper fungicides, such as copper sulfate, are used extensively in the pecan industry for controlling diseases affecting pecan trees.
7. Strobilurins: These are newer systemic fungicides frequently used in turf grass management. They control diseases like brown patch and dollar spot and are used to maintain healthy lawns and golf courses.
8. Botanical and Biological Options: For those interested in organic methods, sulfur is a go-to option. Neem oil, clove oil, rosemary oil, and Bacillus subtilis are also known for their antifungal properties.
Systemic vs. Contact Fungicides
Fungicides can be classified as systemic or contact. Systemic fungicides are absorbed by the plant and move within the plant to ensure more even coverage. They can offer prolonged protection, potentially from 7 to 21 days, depending on the formulation. They may also provide some curative effects if the infection is relatively recent. Contact fungicides, on the other hand, are not absorbed and generally offer protection for 7 to 14 days. They work by creating a protective coat on the plant to prevent fungus spores for growing.
Application Tips
When using fungicides, it's important to read and follow the label instructions carefully. The label will indicate which diseases the product can control, how to apply it, and any necessary safety precautions.
For optimal results and to avoid resistance, you should rotate between different classes of fungicides. Some products combine multiple active ingredients to combat resistance and broader disease spectra.
Fungicides can be applied as liquids or powders, with liquid formulations often preferred for their ease of mixing. However, if using powder, ensure it is well-dissolved before application. Always keep the spray mixture well-agitated to maintain effectiveness.
On fruits and vegetables, be mindful of withdrawal (or pre-harvest interval) periods before harvest, as most fungicides require a specific time to elapse before the treated produce can be safely consumed.
By understanding these basics and applying fungicides correctly, you can help protect your plants from fungal diseases and maintain a healthy garden.
Related Videos:
Mixing and Applying Fungicide
Spraying Fungicide
Related Resources:
Fungicides and Bactericides for Home Fruits, Vegetables, and Ornamentals (UT Redbook)
Using Organic Fungicides