Yellows

Fusarium oxysporum f. sp. conglutinans (Two races have been identified), F. oxysporum f. sp. raphani

Worldwide

Affected foliage turns dull and chlorotic. Some leaves appear distorted due to uneven growth. Leaves may die prematurely and senesce, starting at the base of the plant. This pathogen invades the vascular system of host plants, turning the vascular tissue brown or yellow. Plants that do not die are often stunted and have one-sided yellowing of the leaves or stem.

This 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 generally favored by warm temperatures. At temperatures below 20°C (68°F), disease development is greatly reduced.

Resistant varieties help provide the most effective control of this disease.