University of Florida

Phoma Rot

Fungus

Phoma destructiva

Infects

Foliar plant parts and fruit.

Symptoms

Small black lesions develop on either leaf surface enlarging to about 1/2 in. in diameter, appearing irregular to round in shape, slightly sunken and zonate; stem lesions are elongate but similar; fruit lesions are sunken black spots of increasing size at sites of wounds, insect punctures or stem scar cracks; all foliar and fruit spots develop black pycnidia obvious with hand lens.

Pathogen Spread

By infected transplants or rain-splashed from infected crop debris.

Favorable Conditions

Periods of moderate temperature and high humidity.

Phoma Rot Pictures

phoma rot on leaves
Image #128.
Phoma rot-

on tomato leaf (courtesy R. B. Volin).

phoma rot on fruit
Image # 129.
Phoma-rot-

dark brown to black fruit spots without concentric rings exhibiting pycnidia in the lesion center.