Southern Blight

Authors: Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Last Revised: 01/03/2019 X-number: XHT1042   What is Southern blight?  Southern blight is a lethal fungal disease that is most common in the tropics and subtropics.  This disease causes damage in the southern U.S. and can even cause problems in temperate locations like Wisconsin during periods of warm, moist […]

Tatters

Rachel Leisso* and Brian Hudelson, UW-Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1141 What is tatters? Tatters is a leaf disorder affecting primarily members of the white oak group of oaks (i.e., oaks with leaves with rounded lobes) including bur, white and swamp white oaks.  Members of the red oak group of oaks (i.e., oaks […]

Tubakia (Actinopelte) Leaf Spot

Gina Foreman* and Brian Hudelson, UW-Madison Plant Pathology Revised:  3/11/2012 Item number:  XHT1104 What is Tubakia (Actinopelte) leaf spot?  Tubakia leaf spot, formerly known as Actinopelte leaf spot, is a common late-season leaf disease of oaks.  All species of oak appear to be susceptible to the disease, but oaks in the red oak group (such […]

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 […]

Crown Gall

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  5/5/2005 Item number:  XHT1037 What is a crown gall?  Crown gall is the most widely distributed bacterial disease of plants in the world, affecting over 100 species of fruit crops, and woody and herbaceous ornamentals, including rose, euonymus, lilac, poplar, viburnum, willow, apple, pear, brambles, stone […]

Butternut Canker

Rachel Leisso*, Montana State University Plant Sciences and Plant Pathology* Completed as fulfillment for Plant Pathology Revised:  8/13/2012 Item number:  XHT1142 What is butternut canker?  Butternut canker is a fungal disease of Juglans cinerea, the butternut tree (also known as white walnut or oilnut).  The disease is thought to have originated outside of the U.S.  […]

Black Spot

Adrian Crabb* and Brian Hudelson, UW-Madison Plant Pathology *Completed for Plant Pathology 300 Revised:  8/13/2012 Item number:  XHT1089 What is black spot?  Black spot is a common and potentially serious leaf spot disease affecting many types of roses.  Black spot is found wherever roses are grown. What does black spot look like?  Black spot lesions […]

Dead Man’s Fingers

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1201 What is dead man’s fingers?  Dead man’s fingers is the name of a mushroom-like fungal growth that can be found at the base of dead or dying trees and shrubs, as well as wood objects (e.g., wood barrels) that are in contact […]

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

Powdery Mildew – Trees & Shrubs

Brian Hudelson, UW-Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1005a What is powdery mildew?  Powdery mildew is a disease that occurs on the above-ground parts (especially the leaves) of many deciduous trees and shrubs, as well as herbaceous ornamental plants, indoor houseplants, and many agricultural crops.  Conifers are not affected by this disease. What does […]

Bacterial Canker

Mary Francis Heimann, O.S.F., Distinguished Outreach Specialist emerita at the University of Wisconsin-Madison and Brian Hudelson, UW-Madison Plant Pathology Revised:  12/9/2004 Item number:  XHT1026 What is bacterial canker?  Bacterial canker is a common and sometimes lethal disease of trees in the genus Prunus including cherry, plum and peach.  Bacterial canker is also known as “gummosis”, […]

Fire Blight

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  4/24/2004 Item number:  XHT1090 What is fire blight?  Fire blight is the most destructive bacterial disease affecting plants in the rose family, including apple, pear, crabapple, hawthorn, cotoneaster, mountain ash, quince, rose, pyracantha, and spirea.  It can kill or disfigure a tree or shrub, depending on […]

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