Rose: Botrytis bud and twig blight
Photo by: R.S. Byther
Biology
Botrytis can infect stems and flowers, including stubs left from pruning or flower removal.
Infected tissues are usually covered with a fuzzy, gray-brown growth.
Infected flower buds may not open, and can show sunken, smooth, grayish spots on the bud and flower stem.
Sunken, dead areas may develop on the canes. Infection is worst during cool, wet weather.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Remove all infected portions of plants as soon as the first symptoms appear. This reduces spread of the disease.
- Clean up and destroy all dead plant materials.
- Increase air circulation in plantings by proper spacing and pruning.
- Avoid overhead watering.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Use as a foliar spray but focus on cultural controls.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.