### Basil (*Ocimum basilicum*)

1.  **Basil Downy Mildew** (*Peronospora belbahrii*)
    *   **Integrated Management Strategies:**
        *   **Cultural & Preventive:** The most effective strategy is managing moisture and air. Plant in full sun with wide spacing to promote airflow. Use drip irrigation to avoid wet leaves. For indoor or greenhouse growing, reduce humidity (below 85%) and use fans to circulate air. If possible, grow resistant varieties (e.g., 'Prospera', 'Amazel'). Monitor plants closely, especially the undersides of leaves, and remove infected plants immediately.
        *   **Biological:** Research into biological controls is ongoing. Some biofungicides containing *Bacillus amyloliquefaciens* may provide some preventative suppression.
        *   **Chemical:** Fungicides are most effective when applied preventively. Organic options are limited; some potassium bicarbonate or phosphorous acid-based products have shown some efficacy. Conventional fungicides specifically targeting oomycetes are more effective, with active ingredients like mandipropamid or cyazofamid. Check local regulations, as product availability for herbs is often limited.

2.  **Fusarium Wilt** (*Fusarium oxysporum* f. sp. *basilici*)
    *   **Integrated Management Strategies:**
        *   **Cultural & Preventive:** Plant Fusarium-resistant cultivars ('Nufar', 'Genovese Compact', 'Elidia'). Use certified disease-free seed, as the pathogen can be seed-borne. If the disease has been present, do not plant basil in the same soil for at least 3-4 years. Sanitize all tools, pots, and equipment.
        *   **Biological:** Biofungicides containing *Trichoderma* or *Streptomyces* strains can be incorporated into the soil or potting mix to help suppress the pathogen.
        *   **Chemical:** Fungicides are not effective once the plant is infected. Prevention through resistance and sanitation is key.

3.  **Gray Mold** (*Botrytis cinerea*)
    *   **Integrated Management Strategies:**
        *   **Cultural & Preventive:** Focus on sanitation and air circulation. Remove and destroy any dead or dying leaves and stems promptly. Thin plants to improve airflow. Water in the morning at the base of the plant. In greenhouses, reduce humidity and use fans.
        *   **Biological:** Biofungicides based on *Bacillus subtilis* or *Streptomyces lydicus* can be used preventively.
        *   **Chemical:** Fungicides for *Botrytis* are available but check labels for use on culinary herbs. Active ingredients can include fenhexamid or boscalid. Potassium bicarbonate is an OMRI-listed option that can help manage mild infections.

4.  **Bacterial Leaf Spot** (*Pseudomonas cichorii*)
    *   **Integrated Management Strategies:**
        *   **Cultural & Preventive:** The key is to keep leaves dry. Avoid overhead watering and splashing. Provide good spacing for air circulation. Remove infected leaves or entire plants to reduce inoculum.
        *   **Biological:** None are considered highly effective for active control.
        *   **Chemical:** Copper-based bactericides can be used preventively but have limited effectiveness once the disease is established and can cause phytotoxicity on young basil.

5.  **Damping-Off** (*Rhizoctonia*, *Pythium*, *Fusarium* spp.)
    *   **Integrated Management Strategies:**
        *   **Cultural & Preventive:** Use sterile potting mix and clean containers. Do not overwater seedlings and ensure good drainage. Provide adequate light and air circulation. Sow seeds thinly to avoid overcrowding.
        *   **Biological:** Incorporating a biofungicide containing *Trichoderma harzianum* or *Streptomyces* into the seeding mix can help protect seedlings from infection.
        *   **Chemical:** Fungicide-treated seed is available. A soil drench with a broad-spectrum fungicide labeled for damping-off can be used, but prevention is far more effective.
