Hektar

Pepper white rot Sclerotinia sclerotiorum

Disease Symptoms (Diagnostic Characteristics):

• Basal Stem Discoloration and Rot: Infected plants initially display discolored areas at the base of the stem, which then soften and begin to rot, sometimes forming “canker-like” lesions.
• Whitish Mold and Sclerotia: Affected areas become covered in dense, white mold and sclerotia (hardened fungal structures). When the base of the stem is attacked, plants often turn yellow, wilt, and eventually dry out.
• High Humidity Effects: Under high atmospheric humidity, especially when condensation forms on the foliage, white rot and sclerotia can develop on the stem, sometimes appearing shortly after initial symptoms.

Factors Favoring Disease Development and Spread:

• Humidity and Temperature: This disease frequently impacts pepper and tomato crops in greenhouse settings, with optimal conditions including abundant moisture, condensation on foliage, and temperatures of 16-21°C or slightly higher.
• Host Range: The fungus is polyphagous, meaning it can infect over 360 different plant species.

Prevention and Control Measures:

• Cultural Hygiene: Practice regular removal of infected leaves and fruits, timely defoliation to improve air circulation, and adequate greenhouse ventilation to reduce condensation on foliage, which can trigger rot.
• Fungicidal Treatments: To prevent and control the fungus, alternate treatments with fungicidal products such as:
• Azoxystrobin + Difenoconazole (e.g., Ortiva Top at 0.1%)
• Fenhexamid (e.g., Teldor 500 SC at 0.08%)
• Boscalid + Pyraclostrobin (e.g., Signum at 0.15%)
• Pyrimethanil (e.g., Pyrus 400 SC at 0.15%)
• Fenpyrazamine (e.g., Prolectus at 0.08–0.12%)
• Difenoconazole (e.g., Difcor 250 EC at 0.05%)
• Ecological Control Options: Alternative ecological solutions include defense products or growth inducers, using:
• Seaweed Extracts: Products containing Ascophyllum nodosum and silicon at 0.3-0.5%.
• Organic Fungistatic Extracts: Derived from natural sources like Mimosa.
• Natural Oils: Products with orange oil from the volatile oil category, or those with ethanolamine for foliar applications.