Horseradish Root Rot

Horseradish is a perennial vegetable that thrives when planted in deep, rich, well-drained soil of temperate climate locations. Root rot in horseradish is a fairly common problem caused by over-watering or fungus in the soil.

Cause

Root rot causing fungus is found worldwide in all types of soil. Waterlogged soils produce favorable conditions for the fungus to become active. Sufficient moisture must be present for the fungus to invade the horseradish roots. Without access to oxygen, roots begin to rot and die.

Significance

Root rot produces a visible rotting of the plant's root structure. Commercially, it is responsible for significant reduction in horseradish crop yields. In severe cases, discovery of root rot can leave entire fields unsuitable for growing horseradish for up to three years.

Management

Select only disease-free root cuttings. Grow plants in well-drained, fertile soil. Avoid deep planting, over-watering and over-fertilization. Apply fungicide dust to the top 3 inches of soil in the planting bed. Aerate soils after heavy rains. If possible, rotate the planting area every three to four years.

References

• Utah State University: Horseradish in the Garden; Gilbert Young and Dan Drost; January 2006
• University of Missouri Extension: Horseradish Culture; Keith Hawxby; March 2006
• University of Illinois Extension: Rhizoctonia Disease of Cabbage and Related Crops; Mohammad Babadoost; February 1988