Green Industry - A Knowledge Portal for Commercial Horticulture in Wisconsin (sponsored by University of Wisconsin-Extension)
Diagnostics - Problem Details
Diplodia shoot blight & canker - Diplodia pinea
Description
A shoot tip disorder that can affect a number of pine species.
Damage
Initially you may notice branch tips that ooze a large amount of resin. Eventually, these branch tips brown and die. Often, the newest needles on these dead branches will be of different lengths. As the disease progresses, sunken or swollen, discolored areas (called cankers) may form on infected twigs. Heavy resin flow and an absence of tunnels help distinguish Sphaeropsis shoot blight and canker from damage caused by insect pests.
Cultural Controls
Plant disease free stock. Monitor windbreaks for source of innoculum. Prune only during dry periods and control insects since wounded tissue remains susceptable for several days. Remove red pine windbreaks.
Remarks
Apply in early April through mid-June. Follow label directions. Not proven to be a reliable control.
Chemical Controls
- Azoxystrobin
- Signal Word: Caution
Pesticide Class: Systemic-Upward only - Chlorothalonil+Thiophanate methyl
- Signal Word: Danger
Pesticide Class: Protectant, Systemic-Upward only - Myclobutanil
- Signal Word: Warning
Pesticide Class: Systemic-upward only - Propiconazole
- Signal Word: Warning
Pesticide Class: Systemic-upward only - Thiophanate-methyl
- Signal Word: Caution
Pesticide Class: Systemic-upward only - Triadimefon
- Signal Word: Caution
Pesticide Class: Systemic-upward only
Locations Affected
Plant Environment
Scouting Season:
May - Early , May - Mid , May - Late , June - Early , June - Mid , June - Late , July - Early , July - Mid , July - Late , August - Early , August - Mid , August - Late
Plants Affected
Photos
Branch death on red pine due to Diplodia blight after injury caused by a tornado.
Bark cut away to show cambial necrosis due to Diplodia blight on red pine.
Top kill on Pinus species infected with Diplodia blight.
Typical black fruiting bodies, pycnidia, erupting from needle infected with Diplodia blight.
More fungal fruiting bodies, pycnidia, erupting from Diplodia blight infected red pine needles.
Pycnidia, black fungal fruiting bodies, on Austrian pine twigs infected with Diplodia blight.
Pycnidia, black fungal fruiting bodies, on Austrian pine cone infected with Diplodia blight.
Pycnidia, black fungal fruiting bodies, on red pine cone infected with Diplodia blight.
Shoot blight symptoms on red pine due to Diplodia blight infection several weeks after hail injury.