Disease Directory

    Fusarium Root Rot

    Fusarium solani, Fusarium spp.

    Fungus
    Roots
    Stems

    Overview

    A soil-borne fungal disease causing decay of roots and lower stems in many crops. Unlike Fusarium wilt, this disease primarily attacks root tissue rather than the vascular system. Fusarium Root Rot spreads mainly by spores on wind, splash, tools, and crop debris. Humid, crowded plantings and overhead watering favor outbreaks in home gardens and food forests. Causal agent: Fusarium solani, Fusarium spp.. In regenerative gardens, prioritize sanitation, airflow, and unbroken soil cover over calendar spraying, and intervene early when symptoms appear.

    Symptoms

    Reddish-brown to dark brown lesions on roots and lower stems. Roots become dry and brittle. Stunted growth and yellowing of foliage. Reduced root mass. Plants may wilt under stress but can recover temporarily. Compare several plants and note whether symptoms spread after rain, insect feeding, or wet foliage. Photograph undersides of leaves and cut stems when wilt is present to refine the diagnosis. Rule out simple drought, fertilizer burn, and herbicide drift before assuming a pathogen - abiotic injury often mimics disease.

    Environmental Conditions

    Variable

    Prevention

    Rotate crops. Avoid compacted or waterlogged soils. Use treated seed. Maintain proper soil pH. Plant in well-drained soil. Avoid root injury during cultivation. Mulch to reduce splash, clear season-end debris, and avoid working plants when wet. Design beds for airflow and diverse plantings that support beneficial insects without creating permanent humid pockets around susceptible crops.

    Management

    Improve soil drainage. Apply biological seed treatments (Trichoderma). Reduce soil compaction. Avoid excessive irrigation. Remove severely infected plants. Prefer drip irrigation, morning watering, and open spacing so leaves dry quickly. Disinfect pruners between cuts on woody plants. Use copper, sulfur, or biological products only as labeled protectants when pressure is high - they rarely reverse advanced infections alone. Destroy (do not casually compost) highly infectious debris.