Lime Tree Diseases: Identification, Treatment, and Prevention

Lime trees are heavy feeders that need full sun, excellent drainage, and consistent moisture. Stress from imbalances invites a range of diseases affecting trunk, leaves, fruit, and roots.

Common Problems by Plant Part

Trunk/Stem

• Foot rot / gummosis: Lower stem rot, resin leakage, defoliation. Prune diseased parts; maintain single trunk level.

Leaves

• Curling, gray spots, shiny greasy patches, black mold (from whitefly eggs). Worse in summer.

Fruit

• Rust mites: rust-colored interior.
• Mealybugs: white colonies on stems.
• Weather extremes: fruit drop, cracking, shriveling.

Soil

Prefers warm, sandy/silty, well-aerated soil. Fails in heavy clay or waterlogged conditions.

Major Diseases & Controls

Disease	Cause	Symptoms	Control
Scab	Elsinoë fawcettii	Raised, discolored spots on leaves/fruit	Fungicide spray
Sooty Mold	Citrus whitefly secretions	Black coating on leaves/fruit	Kill whitefly; pest control
Alternaria Brown Spot	Alternaria alternata	Large brown spots with yellow halos; defoliation	Avoid overwater/overfertilize; copper fungicide
Foot Rot	Phytophthora (soil fungus)	Basal stem rot	Prevent injury, control weeds, avoid excess moisture
Root Rot	Phytophthora	Red resin bleeding, yellow leaves, bark cracks	Same as foot rot
Citrus Canker	Xanthomonas axonopodis, leaf miner	Lesions on leaves, stems, fruit; premature drop	Resistant cultivars; bactericide spray
Greasy Spot	Mycosphaerella citri	Yellow-brown greasy spots; defoliation	Fungicide; clean fallen leaves

Preventive Measures

• Remove infected wood; dispose properly.
• Use copper fungicides preventively.
• Remove black-spotted leaves immediately.
• Prefer organic controls; reserve chemicals for severe outbreaks.
• Choose correct pesticide for target pest and growth stage.

Consistent cultural care—proper watering, nutrition, and sanitation—is the best defense against lime tree diseases.