Commercial Disease Controls
The Pennsylvania State University
Cooperative Extension

Horseradish

Disease Control

Damping-Off(Pythium and Phytophthora)
Apply the following preplant incorporated or as a soil-surface spray after planting.

Ridomil Gold--1-2 pt 4E/A

Bacterial Leaf Spot
Rotate to allow 2 years between horseradish plantings. Avoid cultivation or other activity when foliage is wet to minimize spread of the disease.

Cercospora Leafspot, Downy Mildew, Ramularia Leafspot, and White Rust
Practice crop rotation with crops other than crucifers. When conditions favor disease development, apply the following and repeat every 7 to 10 days. Do not make more than two applications.

azoxystrobin (Quadris--6.2 - 15.4 oz 2.08F/A or Amistar--2-5 oz 80WDG/A, or
Cabrio--8-16 oz 20EG/A (labeled for white rust)

Note: Where trade names are used, no discrimination is intended and no endorsement by the Cooperative Extension Service is implied. Information provided is intended for consideration by the user, but is not intended to be a recommendation. Production decisions should be based on consideration of many types of information (scientific, experiential, economic, legal, etc.) available to the user.