Alcoholic Flux of Honey locust
Alcoholic or white flux occurs where microorganisms ferment sap in cracks
and other wounds in the bark and cambial region.
Bacterial Wetwood
Bacterial wetwood is a common disease affecting the central core of many
shade and forest trees. A short discussion and photographs are provided
along with a link for further information.
Blackheart Injury
Blackheart injury is a debilitating factor effected by both rootstock and apple
cultivars. Blackheart, a form of winter injury resulting in the killing
and plugging of xylem tissue, is so named due to the resulting oxidative
brown or black discoloration of the xylem. Blackheart may not cause the
outright death of the tree but has been implicated in tree decline and
reduced productivity. It has been reported that damage may not be apparent
when less than 20% of the xylem is injured, while trees sustaining greater
than 50/% injury may not recover
Black Knot Disease Apiosporina
morbosum
Black knot is a very conspicuous and common disease of most species of
Prunus, including sweet cherry and pin cherry. A photograph of
the canker is provided as well as a discussion of the problem and its
control.
Black Stain Root Disease of Conifers
The black stain fungus infects and kills several species of western conifers.
The fungus colonizes water conducting tissues of the hosts roots, root
collars, and lower stems, ultimately blocking the movement of water to
foliage.
Chestnut Trees a short history of their demise
Chlorosis - A summary of recommended
steps to correction
Accurate and rapid identification of the problem is paramount. A listing
of chlorosis-inducing factors is provided. These should be ruled out before
drawing the conclusion the chlorosis is induced by an Fe deficiency.
Cytospora Canker Cytospora
chrysosperma
Cytospora is a problem of many trees including aspen, cottonwood, poplars,
apple, willow, honey locust and maple. A short discussion and photographs
of this problem are provided. A link to additional information is given.
Cytospora Canker of stone fruit - Peach
Cytospora Canker Leucostoma persoonii
Leucostoma persoonii is a problem of members
of the genus Prunus. This includes peach, apricot, cherry, plum
(prune), nectarine and almond. This fungus can cause tree death in just
a few years after infection.
Fasciations - fascinating distortions
of the plant world
A fasciation is a widespread phenomena reported in more than 100 vascular
plant species. The term refers to a flattened or ribbon-like appearance
of the stem. Woody plants, annuals and even cacti are affected. In some
plants fasciations occur on woody stems; other plants exhibit this condition
in the flower stalk, fruit or flower clusters. Stems, fruits, flowers
and roots can become fasciated.
Frost Cracks
Frost cracks are longitudinal cracks that occur in the bark and wood
often extending several feet up and down and penetrating several inches
into the trunks of affected trees.
Included (embedded) bark
Included bark is embedded between opposing branches, a branch and a main
stem or two co-dominant stems creating a structurally weak point in the
tree.
Natural Needle Loss by Evergreens
Needle loss in the fall is normal for many conifers. Even though these trees are called “evergreens” they do not retain every needle indefinitely.
Phoradendron juniperinum
Juniper mistletoe (Phoradendron juniperinum) is a species of leafless mistletoe that infects Juniperus scopulorum, Juniperus osteosperma, and Juniperus monosperma.
Photos taken on the Colorado National Monument in western Colorado are included.
Powdery Mildew
This provides a photograph of powdery mildew on lilac, lists some susceptible
plants and provides some control options. Additional on-like links and
other references are provided.
Porcupine Damage
Porcupines cause damage by eating the bark off the trunks and branches
of trees.
Quince Rust
Quince rust alternates between Rosaceous hosts and Juniper (Juniperus/Sabina). The Rosaceous hosts of hawthorn rust include Serviceberry [aka Juneberry, Saskatoon & Amelanchier (genus Amelanchier)], apple (Malus), Pear (Pyrus) and Mountain Ash ( Sorbus)
Leaf Scorch
Preventing leaf scorch in trees and shrubs.
Spruce Broom Rust - Chrysomyxa
arctostaphyli
Rust brooms on spruce are commonly associated with spiketops, dead branches,
bole deformation, loss of increment, and mortality.
Sunscald - A mid-winter problem of trunks and branches
Sunscald occurs during cold, bright days in midwinter due to fluctuations
in bark temperature. A discussion of the problem, photographs, control
options and a link to additional information is provided.
Treating gravel roads with magnesium chloride for summer dust control and its affect on spruce trees (Picea engelmanni).
