Causal Agent:
Fusarium oxysporum f. sp. conglutinans. Two races are known.

Distribution:
Worldwide

Symptoms:
The foliage turns a dull green to yellowish color. Some leaves appear warped due to uneven growth. Leaves may die prematurely and drop off, starting at the base of the plant. The vascular system becomes brown or yellow. Plants which do not die become stunted, often with one-sided yellowing of the leaves or stem.

Conditions for Disease Development:
The fungus survives in the soil and produces spores which can persist in the soil for many years. The fungus enters the plant through the roots and moves into the vascular system. Host susceptibility and the environment affect disease development. The disease is favored by warm temperatures. At temperatures below 20°C (68°F) the disease is greatly reduced.

Control:
Resistant varieties provide the most effective control.