White Pine Blister Rust

Joseph Schwartz, UW-Madison Forest Ecology and Management and Glen R. Stanosz, Ph. D., UW Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1118 What is white pine blister rust? White pine blister rust is a serious, tree-killing disease of eastern white pine and its close relatives (pines with needles in bundles of five).  This disease is […]

Root Rots in the Garden

Brian Hudelson, UW-Madison Plant Pathology and Laura Jull, UW-Madison Horticulture Revised:  5/20/2011 Item number:  XHT1072 What is root rot? Root rot is a general term that describes any disease where the pathogen (causal organism) attacks and leads to the deterioration of a plant’s root system.  Most plants are susceptible to root rots, including both woody […]

Winter Salt Injury and Salt-tolerant Landscape Plants

Laura Jull, UW-Extension Revised:  8/13/2012 Item number:  A3877 This publication focuses on recognizing and preventing plant damage caused by deicing salts, evaluates the pros and cons of alternatives to rock salt, and provides an extensive list of salt-tolerant plants.   Download Article

Conifer Disease Quick Reference

Authors: Brian Hudelson, UW-Madison Plant PathologyLast Revised: 04/30/2021D-number: XHT1025 Root and Crown Rots Hosts: All conifers Pathogens: Pythium spp., Phytophthora spp., Rhizoctonia solani, Fusarium spp., Cylindrocarpon spp. Signs/Symptoms:  Poor growth, branch dieback, discolored and deteriorated roots For more information see: UW Garden Facts XHT1070   Rhizosphaera Needle Cast Hosts: Colorado blue spruce, other spruces, many other conifers Pathogen: Rhizosphaera kalkhoffii Signs/Symptoms:  Browning/purpling of interior needles of lower branches, followed by needle drop For more […]

Rhizosphaera Needle Cast

Rhizosphaera needle cast is the most common disease of Colorado blue spruce in Wisconsin. It makes Colorado blue spruce unsightly and unusable in many landscape settings. The disease can also affect other conifers including black, Engelmann, Serbian, Sitka, and white (e.g., Black Hills) spruce; Austrian, mugo and eastern white pine; Douglas-fir, balsam fir and western hemlock.

Phomopsis Tip Blight

Gina Foreman* and Brian Hudelson, UW-Madison Plant Pathology *Completed as partial fulfillment of the requirements for Plant Pathology 875 – Plant Disease Diagnostics Clinic Internship at the University of Wisconsin Madison Revised:  8/13/2012 Item number:  XHT1099 What is Phomopsis tip blight? Phomopsis tip blight is one of the most common fungal diseases of conifers in […]

Herbicide Damage

Brian Hudelson, UW-Madison Plant Pathology Revised:  5/11/2010 Item number:  XHT1004 What is herbicide damage?  Herbicide damage is any adverse, undesired effect on a plant that is caused by exposure of that plant to a pesticide designed for weed control (i.e., a herbicide).  Any plant can be subject to this problem.   What does herbicide damage […]

Dothistroma Needle Blight

Jim Olis* and Brian Hudelson, UW-Madison Plant Pathology *Completed as partial fulfillment of the requirements for a BS in Plant Pathology at the University of Wisconsin Madison. Revised:  8/6/2012 Item number:  XHT1078 What is Dothistroma needle blight? Dothistroma needle blight is a common needle disease that can affect over thirty species of pine trees.  In […]

Diplodia Shoot Blight and Canker

Diplodia shoot blight and canker is one of the most common fungal diseases of Austrian pine in Wisconsin. This disease can also affect other pines including red, jack, Scots and mugo pine, as well as other conifers including cedars, cypresses, firs, junipers and spruces.

Cytospora Canker

Brian Hudelson, UW-Madison Plant Pathology, UW-Extension Revised:  3/11/2012 Item number:  XHT1003 What is Cytospora canker?  Cytospora canker is one of the most common fungal diseases of Colorado blue spruce.  This disease can also affect Norway spruce (and less frequently other spruces) as well as Douglas-fir and balsam fir.  Trees that are 15 years old or […]

Chlorosis

Brian Hudelson, UW-Madison Plant Pathology, UW-Extension Revised:  1/8/2012 Item number:  XHT1002 What is chlorosis?  Chlorosis is a common nutritional disorder of many woody ornamentals in Wisconsin, particularly in the southern and eastern parts of the state.  Pin oaks are most commonly affected by chlorosis, although many other trees and shrubs (e.g., white oak, red maple, […]

Gymnosporangium Rusts

Authors: Brian Hudelson, UW-Madison Plant Pathology Last Revised: 01/23/2019 X-number: XHT1009 What are Gymnosporangium rusts? Gymnosporangium rusts are a group of closely related diseases caused by fungi that infect both junipers (in particular red cedar) and woody plants in the rose family (such as, but not limited to, apple, crabapple, hawthorn and quince). These fungi […]

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