Diplodia Tip Blight
Tip browning of pines is symptomatic of Diplodia tip blight (Diplodia pinea, syn. Sphaeropsis sapinea), a fungal disease.
Most affected are Austrian pine (Pinus nigra) and Ponderosa pine (P. ponderosa), and to a lesser degree, Scots pine (P. sylvestris) and Mugo pine (P. mugo). Diplodia tip blight primarily affects established landscape trees, generally 30 years or older (Ziems, 2008). Untreated, repeat infections can spread from needle fascicles to the entire tree branch, and ultimately result in tree death.
Tip browning in needle bundles, which can spread to the entire branch; dying of branches, can result in tree death.
We recommend treating susceptible trees with Propizol® Fungicide (injection) in the late fall, when resin flow is reduced to aid the uptake of injected Propizol. Use the closer (4 inch) spacing to expedite the application.
When treatments of Propizol® are applied prior to infection, the likelihood of infection is low (the needle bundles or fascicles) would be protected, therefore remain green.
Main photo- taken by Joe Doccola, Arborjet Inc.
Needle 1- Diseased needle fascicles in Austrian Pine, prior to Propizol treatment. Photo taken by Joe Doccola, Arborjet Inc.
Needle 2- New, healthy green needle fascicles, post Propizol treatment. Photo taken by Joe Doccola, Arborjet Inc.
Pine Example 1- Green, healthy; treatment recommended. Photo taken by Joe Doccola, Arborjet Inc.
Pine Example 2- Early infection, some tip browning; treatment recommended. Photo taken by Joe Doccola, Arborjet Inc.
Pine Example 3- Late infection stage, more than 50% of foliage browned; treatment not recommended. Photo taken by Joe Doccola, Arborjet Inc.