{
  "schema_version": "1.0.0",
  "disease_id": "pepper.disease_fungal.blight",
  "aliases": [
    "Phytophthora blight",
    "chile wilt",
    "crown rot"
  ],
  "crop": {
    "common_name": "pepper",
    "scientific_name": "Capsicum annuum",
    "family": "Solanaceae"
  },
  "condition": {
    "common_name": "blight",
    "scientific_name": "Phytophthora capsici",
    "alt_names": [
      "Phytophthora blight",
      "Phytophthora root and crown rot"
    ],
    "pathogen": {
      "type": "disease_oomycete",
      "taxonomy": {
        "kingdom": "Stramenopila",
        "phylum": "Oomycota",
        "class": "Oomycetes",
        "order": "Peronosporales",
        "family": "Peronosporaceae",
        "genus": "Phytophthora",
        "species": "capsici"
      }
    }
  },
  "issue_type": "disease_fungal",
  "transmission": {
    "vectors": [
      "fungus gnats",
      "shore flies"
    ],
    "dispersal": [
      "water splash (rain, irrigation)",
      "contaminated soil",
      "infected transplants",
      "contaminated equipment"
    ],
    "overwintering": [
      "as oospores in soil",
      "in infested plant debris"
    ]
  },
  "environmental_risk": {
    "risk_factors": [
      "poorly drained or heavy clay soils",
      "standing water after heavy rain or irrigation",
      "warm, humid weather",
      "overhead irrigation"
    ],
    "temp_c_day": [
      24,
      29
    ],
    "temp_c_night": [
      18,
      24
    ],
    "relative_humidity_pct": [
      80,
      100
    ],
    "leaf_wetness_hours_threshold": 6
  },
  "severity_rubric": {
    "unit": "qualitative",
    "mild": "Localized lesions on a few leaves or a small, non-girdling stem canker. No wilting is present.",
    "moderate": "Multiple stem cankers, significant leaf blight on several branches, or initial wilting on parts of the plant during the heat of the day.",
    "severe": "Whole plant is permanently wilted, the main stem is girdled by a dark canker at the crown, and the plant is dead or dying.",
    "notes": "Severity is based on the progression of systemic infection. Wilting is a key indicator of moderate to severe infection as it signals root and/or crown rot."
  },
  "symptoms": {
    "leaves": [
      "Small, dark green, water-soaked lesions that expand rapidly into large, irregular tan-to-brown patches.",
      "Affected leaves appear blighted or scalded.",
      "Leaves may drop, leading to defoliation."
    ],
    "stems": [
      "Dark brown to black, water-soaked lesions, most commonly at the soil line (crown rot).",
      "Stem lesions can girdle the stem, causing sudden wilting and collapse of the entire plant.",
      "Cankers can also form on upper stems and branches, causing dieback above the lesion."
    ],
    "fruit": [
      "Large, water-soaked lesions develop, which may be covered with a white, powdery or cottony mold (sporangia) in humid conditions.",
      "Infected fruit shrivels, becomes mummified, and often remains attached to the plant."
    ],
    "roots": [
      "Root system turns dark brown, becomes soft, and decays.",
      "Destruction of the taproot and lateral roots leads to poor water and nutrient uptake."
    ],
    "whole_plant": [
      "Sudden, permanent wilting of the entire plant, often without prior yellowing.",
      "Stunted growth and rapid plant death, especially in wet, warm conditions."
    ],
    "signs_microscopic_or_visible": [
      "White, cottony mycelial growth and powdery-looking sporangia on the surface of fruit or stem lesions during periods of high humidity."
    ]
  },
  "lookalikes": [
    {
      "condition_name": "bacterial_spot",
      "condition_id": "pepper.disease_bacterial.bacterial_spot",
      "key_differences": [
        "Bacterial spot lesions on leaves are small, angular, and often have a 'shot-hole' look, while blight lesions are large, irregular, and water-soaked.",
        "Bacterial spot fruit lesions are raised, rough, and scabby, unlike the soft, moldy rot of blight.",
        "Bacterial spot does not cause the dark, girdling stem cankers at the soil line or the sudden whole-plant wilting characteristic of Phytophthora blight."
      ]
    },
    {
      "condition_name": "anthracnose",
      "condition_id": "pepper.disease_fungal.anthracnose",
      "key_differences": [
        "Anthracnose fruit lesions are distinctly sunken and circular, often with concentric rings and salmon-colored spore masses, whereas blight lesions are water-soaked and covered in white mold.",
        "Anthracnose does not cause crown rot or sudden, total plant wilting.",
        "While anthracnose can cause stem lesions, they are typically less aggressive and do not girdle the stem like Phytophthora blight."
      ]
    },
    {
      "condition_name": "root_rot",
      "condition_id": "pepper.disease_fungal.root_rot",
      "key_differences": [
        "While other root rots (e.g., Pythium, Rhizoctonia) cause wilting, Phytophthora blight is distinguished by the prominent, dark brown to black canker at the soil line (crown rot).",
        "Phytophthora blight also causes aggressive foliar and fruit blight symptoms, which are often absent or less severe with other common root rot pathogens.",
        "Wilting from Phytophthora blight is often more rapid and complete due to the combination of root rot and stem girdling."
      ]
    }
  ],
  "management": {
    "cultural": [
      "Plant in well-drained soil, using raised beds to improve drainage.",
      "Practice careful water management; avoid overwatering and use drip irrigation instead of overhead.",
      "Implement a crop rotation of at least 3 years with non-host crops (e.g., corn, beans).",
      "Sanitize all tools, equipment, and stakes to prevent spread.",
      "Promptly remove and destroy infected plants and surrounding soil."
    ],
    "biological": [
      "Application of soil-drench bio-fungicides containing beneficial microbes like *Trichoderma* spp. or *Bacillus* spp. can help suppress the pathogen."
    ],
    "chemical": [
      "Preventative applications of targeted oomycete-specific fungicides (e.g., mefenoxam, metalaxyl, phosphites) as a soil drench or foliar spray.",
      "Fungicide resistance is a concern; rotate fungicide groups (FRAC codes)."
    ],
    "notes": "An integrated approach is essential. Management relies heavily on preventative cultural practices, as chemical treatments are largely ineffective once the plant is severely infected and wilting."
  }
}