Joseph O'Brien's Images
Title: Plant PathologistOrganization: USDA Forest Service
Unit: Forest Health Protection
Country: United States
Joe is a plant pathologist with the U.S. Forest Service in St. Paul, Minnesota. in addition to photography, his major interests include tree diseases in forests, woodlands and urban areas, hazard tree identification and mitigation, and mycology. Joe is a graduate of the University of Michigan (B.S. Forestry and M.S. Forest Pathology) and the University of Minnesota (Ph.D. Plant Pathology), and currently works at the Northern Research Station on the University of Minnesota's St. Paul campus. |
| 71 Images of 5 Subjects | View Subject List | View Image Details | View Thumbnails |
| Image | Subject Name | Scientific Name | Description |
|---|---|---|---|
| 5040096 | Sirococcus blight of conifers | Sirococcus conigenus | "Deerskin droop" symptoms of Sirococcus conigenus on red pine |
| 5041054 | Diplodia blight | Sphaeropsis sapinea | Dark staining in a twig affected by Diplodia |
| 5041055 | Diplodia blight | Sphaeropsis sapinea | Dark staining of the wood |
| 5041077 | Diplodia blight | Sphaeropsis sapinea | Shoot blight. Several people examining symptoms during a field tour. |
| 5041076 | Diplodia blight | Sphaeropsis sapinea | Severe Diplodia shoot blight episode, following a hailstorm |
| 5041091 | Diplodia blight | Sphaeropsis sapinea | Setting up a research plot to track impacts of shoot blight. |
| 5041092 | Diplodia blight | Sphaeropsis sapinea | Setting up a research plot |
| 5041093 | Diplodia blight | Sphaeropsis sapinea | Marking trees to track shoot blight impacts |
| 5041097 | Diplodia blight | Sphaeropsis sapinea | Shoot blight symptoms |
| 5041098 | Diplodia blight | Sphaeropsis sapinea | Shoot blight symptoms |
| 5041099 | Diplodia blight | Sphaeropsis sapinea | Shoot blight symptoms under a red pine shelterwood |
| 5039004 | Diplodia blight | Sphaeropsis sapinea | Collar rot in jack pine caused by Diplodia |
| 5031049 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | |
| 5031068 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | |
| 5031055 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast on white spruce. Off color foliage. |
| 5031050 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast associated with a decline of white spruce in Wisconsin |
| 5031053 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast on lower branches of white spruce. |
| 5031054 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast on white spruce windbreaks in a nursery. |
| 5031060 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Off color foliage infected with Rhizosphaera kalkhoffii. |
| 5031056 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast symptoms on white spruce. |
| 5031058 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Sporocarps of Rhizosphaera emerge from the stomata. The sporocarps are black, and the stomata are often capped with a white waxy plug, which sometimes can be seen on the top of the sporocarps. |
| 5031059 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Symptoms of Rhizosphaera needle cast, which can be a component of the spruce decline syndrome. |
| 5031047 | Rhizosphaera needle cast | Rhizosphaera kalkhoffii | Rhizosphaera needle cast on white spruce. |
| 5030045 | oak anthracnose | Apiognomonia errabunda | |
| 5030047 | oak anthracnose | Apiognomonia errabunda | |
| 5030049 | oak anthracnose | Apiognomonia errabunda | |
| 5030050 | oak anthracnose | Apiognomonia errabunda | |
| 5030057 | oak anthracnose | Apiognomonia errabunda | |
| 5040094 | Sirococcus blight of conifers | Sirococcus conigenus | current year shoots |
| 5040095 | Sirococcus blight of conifers | Sirococcus conigenus | droop symptoms |
| 5042003 | Diplodia blight | Sphaeropsis sapinea | top kill |
| 5041073 | Diplodia blight | Sphaeropsis sapinea | seedling mortality in understory |
| 5041074 | Diplodia blight | Sphaeropsis sapinea | severe infection in large tree |
| 5041078 | Diplodia blight | Sphaeropsis sapinea | |
| 5041080 | Diplodia blight | Sphaeropsis sapinea | shoot blight in overstory |
| 5041081 | Diplodia blight | Sphaeropsis sapinea | shoot blight in overstory |
| 5041082 | Diplodia blight | Sphaeropsis sapinea | shoot blight in windbreak |
| 5041083 | Diplodia blight | Sphaeropsis sapinea | |
| 5041084 | Diplodia blight | Sphaeropsis sapinea | shoot blight in understory |
| 5041086 | Diplodia blight | Sphaeropsis sapinea | shoot blight on overstory branch |
| 5041087 | Diplodia blight | Sphaeropsis sapinea | |
| 5041088 | Diplodia blight | Sphaeropsis sapinea | shoot blight on understory tree |
| 5041090 | Diplodia blight | Sphaeropsis sapinea | |
| 5041095 | Diplodia blight | Sphaeropsis sapinea | |
| 5041096 | Diplodia blight | Sphaeropsis sapinea | |
| 5041056 | Diplodia blight | Sphaeropsis sapinea | branch mortality |
| 5041057 | Diplodia blight | Sphaeropsis sapinea | cambial staining |
| 5041059 | Diplodia blight | Sphaeropsis sapinea | canker on main stem |
| 5041060 | Diplodia blight | Sphaeropsis sapinea | discolored wood |
| 5041065 | Diplodia blight | Sphaeropsis sapinea | |
| 5040097 | Sirococcus blight of conifers | Sirococcus conigenus | repeated infection |
| 5040098 | Sirococcus blight of conifers | Sirococcus conigenus | |
| 5041001 | Sirococcus blight of conifers | Sirococcus conigenus | |
| 5041003 | Sirococcus blight of conifers | Sirococcus conigenus | |
| 5041005 | Sirococcus blight of conifers | Sirococcus conigenus | |
| 5041006 | Sirococcus blight of conifers | Sirococcus conigenus | |
| 5041007 | Sirococcus blight of conifers | Sirococcus conigenus | |
| 5041053 | Diplodia blight | Sphaeropsis sapinea | |
| 5040078 | Diplodia blight | Sphaeropsis sapinea | shelterwood modified after Sphaeropsis |
| 5040079 | Diplodia blight | Sphaeropsis sapinea | shelterwood with Sphaeropsis |
| 5040080 | Diplodia blight | Sphaeropsis sapinea | shelterwood with Sphaeropsis |
| 5034094 | oak anthracnose | Apiognomonia errabunda | |
| 5034096 | oak anthracnose | Apiognomonia errabunda | |
| 5038035 | Diplodia blight | Sphaeropsis sapinea | |
| 5032018 | oak leaf blister | Taphrina caerulescens | |
| 5041067 | Diplodia blight | Sphaeropsis sapinea | |
| 5041068 | Diplodia blight | Sphaeropsis sapinea | |
| 5041069 | Diplodia blight | Sphaeropsis sapinea | |
| 5041070 | Diplodia blight | Sphaeropsis sapinea | |
| 5041071 | Diplodia blight | Sphaeropsis sapinea | |
| 5041072 | Diplodia blight | Sphaeropsis sapinea |
