Botrytis Bud and Twig Blight

Botrytis cinerea

19 host plants · Fungal

Last updated

Data Maturity Structured

This profile synthesizes data from multiple published sources. Expert field review is in progress.

Botrytis bud and twig blight causes bud death and twig dieback on susceptible hosts. You'll notice brown, fuzzy fungal growth on affected buds and shoots during cool, moist weather. The disease favors spring conditions with cool temperatures and high humidity. Remove infected buds and twigs promptly, improve air circulation, and avoid overhead watering that keeps plants wet.

Collect and destroy infected plant debris and tissues from and around the plant. Maintain a steady, relatively dry environment by keeping greenhouse humidity below 90%, increasing spacing between plants for good air circulation, and taking care not to splash water on foliage during watering.

Quick Reference

Agent Type
fungal
Causal Agent
Botrytis cinerea
Host Plants
19
Spread
Conidia dispersed by air currents, water splash, and changes in relative humi...
Favorable Conditions
5-8 hours continuous high humidity (>90%) or leaf wetness at 60-77°F (15-25°C...

Management

Vulnerability Window

During flowering and bloom; dormancy wounds from normal winter pruning; cold-damaged buds and shoots in early spring; moist storage conditions on nursery stock and cut flowers.

What Triggers Infection

5-8 hours continuous high humidity (>90%) or leaf wetness at 60-77°F (15-25°C); optimum 65-73°F. Infection requires moist, humid environment; conidia germinate readily on wet surfaces. Cold injury, frost damage, or mechanical wounding increase susceptibility. # Source: PNW Plant Disease Management Handbook

Cultural Controls

  • Collect and destroy infected plant debris and tissues from and around the plant.
  • Maintain a steady, relatively dry environment by keeping greenhouse humidity below 90%, increasing spacing between plants for good air circulation, and taking care not to splash water on foliage during watering.
  • Heating the greenhouse at night (especially for zero or negative DIF) or venting around sunset may be necessary.
  • Heating in the morning before sunup can also help prevent dew formation as air temperature increases faster than the temperature of plant parts.
  • If using DROP or DIP for size control, do not let humidity rise above 90%.
  • Space plants for adequate air movement.

Host Plants (19)