Diplodia

What is it?

Fungus that attacks needles on Pine trees. It can kill trees over the course of time as the tree thins out and becomes weaker.

What are the signs?

• Browning needle tips
• Sudden needle drop
• Thin appearance

Shepherd’s crook caused by Diplodia shoot blight. Photo Credit: Elizabeth Bush, Virginia Polytechnic Institute and State University, Bugwood.org

Life Cycle

• Spores form in spring on new growth during candle elongation
• Once the candles harden for the year, you cannot treat the tree for that season
• Wet conditions/Humid conditions drive disease spread

Treatment/Prevention

• Growth Regulator treatment to slow tree growth
• Low nitrogen fertilizer for increased tree immunity and health
• Tree fungicide applications (2-3) applications per year
• 3 years of treatment is typically needed