Southport Red Globe Onions

FBR - Fusarium Basal Rot

Scientific Name: Fusarium oxysporum f. Sp. Cepea

Type: Fungus

Fusarium Basal Rot is a world-wide soil borne disease that affects the growth of chives, garlic, leeks, onions, and shallots. The disease can start at any stage of the growth of the onion, but usually begins during bulb formation. Symptoms of wilting of the leaves may occur and the leaves turn a yellow color and start to die off. Onions infected with Fusarium Basal Rot often show a red-brown color on the stems and roots, then progressing to a dark brown color. White fungus will develop at the base of the plant and the plant will eventually die. The surviving plants will have bulbs that become soft and non-desirable. The disease is not often noticed until onions are harvested when moldy roots are exposed. Protect the onion plants from insect, especially root maggots, to avoid the spreading of the disease to other plants and further damage to bulb. The disease tends to occur when planted in poorly drained soil, so try to improve soil conditions and utilize raised beds techniques. The disease is also favorable when temperatures are 82-90 F, and usually occur between mid to late summer. Plan on using a 4 year crop rotation and avoid planting onions in the same location, year after year as the disease can survive in the soil for a long time. The best option is to use disease resistant varieties and/or use a root fungicide for soil based diseases.