Diseases of Diseases Populus Populus Diseases of Populus in British Columbia: A Diagnostic Manual Manual Columbia: A Diagnostic in British in British Columbia: A Diagnostic Manual Brenda E. Callan Brenda Brenda E. Callan Natural Resources Ressources naturelles Canada Canada Canadian Forest Service canadien ISBN No. 0-662-27084-3 Service des forêts Acknowledgements The author is very grateful to Eric Allen, Leland Humble, Rich Hunt, Tony Hunt, Duncan Morrison, and George Newcombe for reviewing various sections, providing helpful suggestions, and permission to use unpublished information. Special thanks to technicians who worked with the author at the Pacific Fo re s t ry Centre : Analie Fernando for assistance with photomicroscopy, Fiona Ring for assistance with initial field s u rveys, photographs and collections, and Paul Spencer for creating an index and calculating scales for photographs. Nicola Par fett and Rob e r t Erickson created data sets from historical For est Insect and Dis e a s e Sur vey rec o r ds, and used them to develop the distribution maps of common poplar diseases. Steve Glover and Jennifer Adsett patiently guided the editorial process and made layout and printing arrangements. Layout was done by TM Communications Inc., Victoria. The author was generously permitted to use photographs taken by many current and former Canadian For est Ser vice field technicians and scientists, as well as colleagues from other agencies. The publication of this book was made possible by financial support from Forest Renewal British Columbia Research Award PA 97684. Diseases of Populus in British Columbia: A Diagnostic Manual vii Contents Acknowledgements .................................................................................................... vii Photo Credits ............................................................................................................. viii How to Use this Book ................................................................................................ ix Introduction ............................................................................................................... 1 The Poplar Resource in British Columbia............................................................... 1 Taxonomy and Distribution................................................................................... 2 Field and Laboratory Techniques ............................................................................... 6 Field Collection of Tree Diseases............................................................................. 6 Foliar diseases .................................................................................................... 6 Stem or branch cankers (< 10 cm in diameter)................................................... 6 Stem or branch cankers (> 10 cm in diameter)................................................... 6 Wood decay samples.......................................................................................... 6 Standing dead or dying trees with suspected root disease ................................... 7 Blowdown with decay ........................................................................................ 7 Wood decay mushrooms.................................................................................... 7 Common Mounting Solutions Used for Microscopic Examination ........................ 8 Diagnostic Reagents ............................................................................................... 8 Abiotic Diseases and Virus-like Symptoms................................................................. 10 Arthropod Damage..................................................................................................... 16 Arthropod Damage Often Confused with Poplar Diseases...................................... 16 Mite Stem and Branch Galls................................................................................... 20 Leaf-bronzing Disease of Cottonwood and Hybrid Poplar...................................... 23 Vertebrate Damage ..................................................................................................... 26 Cankers and Bark Diseases ......................................................................................... 29 Key to Common Cankers and Bark Diseases.......................................................... 30 Blackstem Disease of Hybrid Poplars and Cottonwood .......................................... 32 Cytospora Canker................................................................................................... 35 Sooty-bark Canker ................................................................................................. 39 Ceratocystis Canker................................................................................................ 42 Cryptosphaeria Canker........................................................................................... 45 Hypoxylon Canker................................................................................................. 48 Neofabraea Canker of Poplars................................................................................. 53 Bark Deformity Diseases of Poplars ........................................................................ 56 Rough-bark Diseases of Aspen........................................................................... 56 Aspen Stem Galls and Bark Proliferation ........................................................... 59 Cork-bark of Cottonwood................................................................................. 60 Foliar Diseases and Shoot Blights............................................................................... 62 Key to Common Foliar Diseases and Shoot Blights ................................................ 63 Ink Spot Disease of Aspen ...................................................................................... 66 Linospora Leaf Blight............................................................................................. 68 Marssonina Leaf Blights ......................................................................................... 72 Leaf Rusts of Cottonwood and Hybrid Poplar........................................................ 78 Diseases of Populus in British Columbia: A Diagnostic Manual v Leaf Rust of Aspen ................................................................................................. 86 Septoria Leaf Blight of Cottonwoods and Hybrid Poplars....................................... 89 Taphrina Leaf Blister and Leaf Curl of Poplars........................................................ 94 Aspen Shoot and Leaf Blight ................................................................................. 97 Poplar Leaf and Shoot Blight .................................................................................. 102 Other Foliar Diseases.............................................................................................. 106 Root Diseases and Wood Decay ................................................................................. 109 Key to Common Non-gilled Wood Decay Fungi.................................................... 111 Key to Four Common Mushrooms Associated with Decay ..................................... 112 Armillaria Root Diseases......................................................................................... 113 White Mottled Trunk and Butt Rot........................................................................ 119 Peniophora Decay .................................................................................................. 122 Aspen Trunk Rot .................................................................................................... 125 Other Decay Organisms ......................................................................................... 129 Glossary...................................................................................................................... 134 General Index ............................................................................................................. 138 Host-fungus Index for Populus in British Columbia.................................................. 151 vi Diseases of Populus in British Columbia: A Diagnostic Manual Acknowledgements The author is very grateful to Eric Allen, Leland Humble, Rich Hunt, Tony Hunt, Duncan Morrison, and George Newcombe for reviewing various sections, providing helpful suggestions, and permission to use unpublished information. Special thanks to technicians who worked with the author at the Pacific Fo re s t ry Centre : Analie Fernando for assistance with photomicroscopy, Fiona Ring for assistance with initial field s u rveys, photographs and collections, and Paul Spencer for creating an index and calculating scales for photographs. Nicola Par fett and Rob e r t Erickson created data sets from historical For est Insect and Dis e a s e Sur vey rec o r ds, and used them to develop the distribution maps of common poplar diseases. Steve Glover and Jennifer Adsett patiently guided the editorial process and made layout and printing arrangements. Layout was done by TM Communications Inc., Victoria. The author was generously permitted to use photographs taken by many current and former Canadian For est Ser vice field technicians and scientists, as well as colleagues from other agencies. The publication of this book was made possible by financial support from Forest Renewal British Columbia Research