Leyland cypress has actually become one of the many widely offered plants in commercial and residential landscapes across Georgia as a formal hedge, display, buffer spilgrimage, or wind obstacle. Leyland cypress (x Cupressocyparis leylandii) is a graceful, swiftly flourishing evergreen tree that is adapted for expansion within the 6-10a USDA hardiness zones. The tree is ideal suited for productive, well-drained soils. However, when young, the tree will certainly prosper up to 3-4 feet per year, even in poor soils. The tree will eventually achieve a majestic height of as much as 40 feet. Leyland cypush forms a dense, oval or pyramidal outline when left unpruned, however the sleek, slightly pendulous branches will certainly toleprice severe trimming to develop a formal hedge, screen or windbreak. The fine, feathery foliage is composed of soft, pointed leaves on flattened branchallows, dark blue-green once mature however soft and bright green as soon as young.

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Leyland cypush is thought about reasonably pest-free. However, because of its reasonably shenable root system, and because they are frequently planted too cshed together and also in poorly drained soils, Leyland cypush is at risk to root rot and also several damaging canker diseases, particularly in the time of periods of expanded drought. Disease monitoring is, therefore, a consideration for Leyland cypush.

Diseases

Seiridium Canker and also Twig Dieback

In Georgia, Seiridium canker is most likely the many important and also devastating illness on Leyland also cypush in the landscape. Although the fungi Seiridium cardinale, Seiridium unicorne, and Seiridium cupressi have been reported to reason disease on Leyland cypress and various other needled evergreens, only Seiridium unicorne is a lot of commonly connected with cankers and twig dieearlier on Leyland also cypress in Georgia. In the landscape, plants of all sizes and eras deserve to be impacted by the illness.

Symptoms

One of the a lot of noticeable symptoms of Seiridium canker is yellowing or browning of the foliage on one or more height or lateral branches. The discoloration is most most likely to appear in early on spring; but, it have the right to be seen at any kind of time of the year. The condition growth frequently continues till a far-ranging portion of the tree is ruined. Upon closer examination, development of many thin, elongated cankers is observed on stems, branches and also branch axils. These cankers cause twig and branch dieback. Most of the cankers are slightly sunken, through elevated margins, and they may be discolored dark brvery own to purple. Cracked bark in infected locations is regularly accompanied by comprehensive resin exudates that flow down the diseased branches. The cambial tissue beneath oozing sites is discolored via a reddish to brvery own shade.


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" width="215"/> Figure 2. Branch and twig dieback symptoms of Seiridium canker.
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" width="220"/> Figure 3. Branch dieago symptoms of Seiridium canker.
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" width="275"/> Figure 4. Oozing at the website of Seiridium cankers.

In the landscape, the causal agent, Seiridium unicorne, over-seasons in cankers on diseased trees. Environmental stress, predominantly drought stress and anxiety, favors infection and also canker development. Seiridium cankers enbig approximately three times much faster on drought stressed trees than on adequately irrigated trees. Spring freeze and ice injury regularly predisposes trees to infection. Fruiting bodies of the pathogen, called acervuli, show up on the canker as little black dots that are barely visible to the naked eye. Fungal spores are spcheck out to various other parts of an infected tree or to other trees by splashing water either from rain or irrigation. The fungus also deserve to be spcheck out on pruning tools. Long distance spcheck out occurs through the deliver of infected cuttings or plants, or possibly by insects. New infections take place when spores lodge in bark cracks and also wounds. Infection through lenticels may happen complying with hot, dry weather.

Control

Ideal facility and care are the finest defenses versus Seiridium canker in residential and commercial landscapes. Due to its fairly shpermit root system, plant Leyland cypush in tilled and amfinished soils to encourage plant vigor. Avoiding extreme watering and also warmth anxiety is necessary to facility of a healthy Leyland also cypress.

To minimize water loss and also water competition through various other plant species such as turf, mulch a space several feet past the lowest limbs. During hot, dry summer days, irrigate trees thoapproximately about the base of the tree every 7-14 days, relying on soil composition. Take distinct care for trees situated near drive-methods, paved locations or heat-showing structures. Providing adequate irrigation in the time of durations of drought is the best defense against Seiridium canker illness.

Sanitation, such as removal of cankered twigs and also branches, helps proccasion disease spread. Destroy pruned products, and also disinfect pruning devices by rinsing in rubbing alcohol or a solution of 1 component bleach to 9 components water. Rerelocate broadly damaged trees or trees that are damaged in the primary trunk.

No cultivars or selections are known to be resistant to the illness. In the landscape, fungicides are hardly ever supplied and also they provide no regulate once an infection has actually taken location.

Botryosphaeria (Bot) Canker

Anvarious other damaging condition on Leyland also cypush in Georgia landscapes is a canker and also dieago named Botryosphaeria (Bot) canker, resulted in by the fungus Botryosphaeria dothidea. This aggressive disease affects a variety of woody shrubs and also trees global, and also it has actually been reported on azaleas, rhododendrons, flowering dogwoods and redbuds, among others. Plants enduring from ecological stresses (freezing, drought, or heat) or wounds are particularly prone to B. dothidea infection in landscape plantings.

Symptoms
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" width="275"/> Figure 5. Dark, rust-colored dieback symptoms of Botryosphaeria (Bot) canker.

In the landscape, Bot canker symptoms resemble those caused by Seiridium canker. Bright, rust-colored branches and also yellowing or browning of shoots or branches are the initially observed symptoms. Closer inspection reveals the visibility of sunken, girdling cankers at the base of the dead shoot or branch. Sometimes, the major trunk shows cankers that can extend for a foot or even more in size. These cankers seldom girdle the trunk, but they will kill branches that may be encompassed by the canker as it grows.

Canker surdeals with might be cracked and also have actually a darker shade than the neighboring healthy and balanced bark. The discoloration regularly extends several inches below the canker perimeter. Little or no resin "oozing" is developed on the infected areas.

Disease Cycle and also Epidemiology of the Disease

The Bot canker fungus survives in the bark and in various other dead tworries of Leyland also cypush, yet it could likewise make it through on hold shrubs and trees. Fruiting bodies of the fungus are installed beneath the bark, but their existence deserve to be discerned as tiny, raised pimples scattered over the surface of the canker.

As in Seiridium canker, the spores of the fungus are spreview by splashing water from rain or watering and also by infested pruning tools. Long distance spread is through the deliver of infected cuttings or plants, or probably by insects. Spores of B. dothidea might likewise be spreview by wind.

Control

Due to the complace of many kind of of Georgia"s soils, create brand-new plantings of Leyland cypress in tilled and well-drained locations. Till locations 3-4 times the diameter of the root ball, and also amend soils as needed. Percreate a soil fertility test, and readjust soils through lime and also fertilizer as recommended. Set the tree at or just over the soil level. Avoid eco-friendly and social stresses that predispose the plants to infection, as said for Seiridium canker.

To minimize water loss and water competition, mulch an area a number of feet past the lowest limbs. Removal of diseased twigs and branches helps proccasion illness spreview. Remove and also damage pruned material and also disinfect pruning tools. Remove generally damaged trees. In the landscape, no fungicides are recommended to regulate Bot canker.

Root Rot Diseases

Albeit inregular, root rot conditions on Leyland Cypress deserve to be essential. Two root conditions deserve to influence Leyland cypush -- Phytophthora root rot, resulted in by the water mold Phytophthora cinnamomi, and Annosum root rot, brought about by the basidiomycete fungus Heterobasidion annosum.

In the landscape, Phytophthora root rot generally affects root units of smaller sized plants; huge, establimelted trees are rarely affected by the disease. The pathogen is more damaging in cases where soil drainage is bad. Plants via serious root damage exhibit stunted growth, general yellowing of the foliage, smaller branches and also needles, and reminder dieback. In significant cases, plants will certainly die.


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" width="210"/> Figure 6. Tree killed by Phytophthora root rot.

Decayed, darkened roots are a symptom of the disease; but, Phytophthora root rot can just be diagnosed via certainty by laboratory evaluation of affected roots. To protect against Phytophthora root rot, establish Leyland cypush in tilled and also well-drained soils. Avoid over-irrigating trees, particularly in the time of establishment, and follow all cultural techniques as described for the regulate of the canker illness. Chemical control is not recommfinished for landscape trees.

Annoamount root rot is uncommon on Leyland also cypush in Georgia landscapes. Trees at new building and construction sites, particularly those located on urban-wild land also interencounters and also wright here pine clearing has actually taken area, are even more vulnerable to the advance of this illness.

Disease creates via fungal spore infection of freshly reduced pine stumps. The fungus then grows through the stump and also its root system, infecting nearby Leyland also cypush trees with root contact.

Symptoms of Annosum root rot incorporate the decay and fatality of bigger roots on freshly infected plants. Foliage symptoms include yellowing and also sluggish decline, adhered to by death of the tree. in some cases, yet, the foliage on the entire tree all of a sudden turns reddish-brvery own. Some trees might feverywhere before any kind of crown symptoms are existing. Basidiocarps (huge mushroom-favor structures) are apparent at the base of an infected tree, usually beneath the mulch or leaf litter. These frameworks are generally tiny, ircontinual in form, brvery own on the upper surface and also white on the lower surconfront.

Tbelow is no reliable manage when the tree is infected. As a preventive meacertain, rerelocate the stumps of felled conifers completely or treat the stump surchallenge via borax immediately after the tree is felled.

References

Alabama Cooperative Exanxiety Service http://www.aces.edu/pubs/docs/A/ANR-1160/

Benson, M., et al. http://www.ces.ncsu.edu/depts/pp/notes/Ornamental/odin17/od17.htm

Hansen, M., and also Lewis, K. J., eds. 1997. Compendium of Conifer Diseases. American Phytopathological Society, St. Paul, Minn.

Sinclair, W. A., Lyon, H. H., and also Johnkid, W. T. 1987. Diseases of Trees and also Shrubs. ComstockPublishing Associates, Cornell University Press, Ithaca, N.Y.

Tisserat, N. A., Nus, A., and Barnes, L. W. 1991. A canker disease of the Cupressaceae in Kansas and Texas caused by Seiridium unicorne. Plant Dis.75:138-140.

Williams-Woodward, J., and Windham, M.T. 2002. Diseases of Leyland also Cypress.

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On Diseases of woody ornamentals on nurseries. American Phytopathological Society, St. Paul, Minn.

1Exanxiety Plant Pathologists2IPM Homeowner Specialist, Plant Pathology, Griffin Campus

Status and also Revision History Publimelted on Apr 17, 2003Publiburned on Feb 10, 2009Publiburned through Full Rewatch on Feb 10, 2012Publimelted via Full Recheck out on Feb 17, 2015


Alfredo Martinez Professor and Exstress and anxiety Plant Pathologist-Turfgrass, Small Grains, Non-Legume Forperiods, Plant Pathology Jean Williams-Woodward Exstress Plant Pathologist - Ornamentals, Foresattempt, Christmas Trees, Legume Forperiods, Plant Pathology