The pathogenic fungus Cryphonectria parasitica is a member of the Ascomycota. This necrotrophic fungus is native to East Asia and South East Asia and was introduced into Europe and North America in the early 1900s. The fungus spread rapidly and caused significant tree loss in both regions.
Diplodia tip blight, also known as Sphaeropsis blight, is a widespread disease affecting conifers caused by an opportunistic fungal pathogen, Diplodia sapinea. It is found in “both hemispheres between the latitudes 30° and 50° north and south". The diseases symptoms include: damping off and collar rot of seedlings, stem canker, root disease, and, most commonly, shoot blight. These symptoms have caused significant economic loss to nurseries and pine plantations. In a nursery in the north-central United States, losses of 35% have been reported. Shoot blight and eventual die back can cause a reduction of marketable volume in timber by 63%. Infection of terminal shoots can result in dead-top which significantly limits the usable length of the tree trunk. The presence of the pathogen in concert with severe weather conditions can lead to extreme loss. Following a severe hailstorm in South Africa, nearly 5,000 acres of pine plantation were infected with Diplodia tip blight. It was necessary to prematurely harvest large swaths of the plantations resulting in a loss of 45%. Areas that were not harvested prematurely still suffered an average timber loss of 11%.
Ophiostoma ulmi is a species of fungus in the family Ophiostomataceae. It is one of the causative agents of Dutch elm disease. It was first described under the name Graphium ulmi, and later transferred to the genus Ophiostoma.
Monilinia fructicola is a species of fungus in the order Helotiales. A plant pathogen, it is the causal agent of brown rot of stone fruits.
Leptosphaeria coniothyrium is a plant pathogen. It can be found around the world.
Nectria cinnabarina, also known as coral spot, is a plant pathogen that causes cankers on broadleaf trees. This disease is polycyclic and infects trees in the cool temperate regions of the Northern Hemisphere. N. cinnabarina is typically saprophytic, but will act as a weak parasite if presented with an opportunity via wounds in the tree or other stressors that weaken the tree's defense to the disease. A study published in 2011 showed that this complex consists of at least 4 distinct species. There are only a few ways to manage this disease with techniques such as sanitation and pruning away branches that have the cankers. N. cinnabarina is not as significant a problem as other Nectria spp., some of which are the most important pathogens to infect hardwood trees.
Botryosphaeria ribis is a fungal plant pathogen that infects many trees causing cankers, dieback and death.
Diaporthe helianthi is a fungal pathogen that causes Phomopsis stem canker of sunflowers. In sunflowers, Phomopsis helianthi is the causative agent behind stem canker. Its primary symptom is the production of large canker lesions on the stems of sunflower plants. These lesions can eventually lead to lodging and plant death. This disease has been shown to be particularly devastating in southern and eastern regions of Europe, although it can also be found in the United States and Australia. While cultural control practices are the primary method of controlling for Stem Canker, there have been a few resistant cultivars developed in regions of Europe where the disease is most severe.
Anisogramma anomala is a plant pathogen that causes a disease known as Eastern filbert blight on Corylus spp. (hazlenut). Also known as EFB.
The plant pathogenic fungus Leucostoma kunzei is the causal agent of Leucostoma canker, a disease of spruce trees found in the Northern Hemisphere, predominantly on Norway spruce and Colorado blue spruce. This disease is one of the most common and detrimental stem diseases of Picea species in the northeastern United States, yet it also affects other coniferous species. Rarely does it kill its host tree; however, the disease does disfigure by killing host branches and causing resin exudation from perennial lesions on branches or trunks.
Didymella bryoniae, syn. Mycosphaerella melonis, is an ascomycete fungal plant pathogen that causes gummy stem blight on the family Cucurbitaceae, which includes cantaloupe, cucumber, muskmelon and watermelon plants. The anamorph/asexual stage for this fungus is called Phoma cucurbitacearum. When this pathogen infects the fruit of cucurbits it is called black rot.
Porodaedalea pini, commonly known as the pine conk, is a species of fungus in the family Hymenochaetaceae. It is a plant pathogen that causes tree disease commonly known as "red ring rot" or "white speck". This disease, extremely common in the conifers of North America, decays tree trunks, rendering them useless for lumber. It is a rot of the heartwood. Signs of the fungus include shelf-shaped conks protruding from the trunks of trees. Spores produced on these conks are blown by the wind and infect other trees. Formal management of this disease is limited, and the disease is controlled primarily by cultural practices. Red ring rot is an important forest disturbance agent and plays a key role in habitat formation for several forest animals.
Diaporthe phaseolorum var. sojae is a plant pathogen infecting soybean and peanut.
Ceratocystis coerulescens is an ascomycete fungus and the causal agent of sapstreak disease in sugar maple trees. There is debate about whether it is one species or two; the second being Ceratocystis virescens. For simplicity, this page will refer to this pathogen as one species. It is also known by its anamorph name Endoconidiophora virescens.
Dibotryon morbosum or Apiosporina morbosa is a plant pathogen, which is the causal agent of black knot. It affects members of the Prunus genus such as; cherry, plum, apricot, and chokecherry trees in North America. The disease produces rough, black growths that encircle and kill the infested parts, and provide habitat for insects.
Armillaria root rot is a fungal root rot caused by several different members of the genus Armillaria. The symptoms are variable depending on the host infected, ranging from stunted leaves to chlorotic needles and dieback of twigs and branches. However, all infected hosts display symptoms characteristic of being infected by a white rotting fungus. The most effective ways of management focus on limiting the spread of the fungus, planting resistant species, and removing infected material. This disease poses a threat to the lumber industry as well as affecting recreational areas.
Fusarium circinatum is a fungal plant pathogen that causes the serious disease pitch canker on pine trees and Douglas firs. The most common hosts of the pathogen include slash pine, loblolly pine, Monterey pine, Mexican weeping pine, and Douglas fir. Like other Fusarium species in the phylum Ascomycota, it is the asexual reproductive state of the fungus and has a teleomorph, Gibberella circinata.
Pine-pine gall rust, also known as western gall rust, is a fungal disease of pine trees. It is caused by Endocronartium harknessii, an autoecious, endocyclic, rust fungus that grows in the vascular cambium of the host. The disease is found on pine trees with two or three needles, such as ponderosa pine, jack pine and scots pine. It is very similar to pine-oak gall rust, but its second host is another Pinus species. The fungal infection results in gall formation on branches or trunks of infected hosts. Gall formation is typically not detrimental to old trees, but has been known to kill younger, less stable saplings. Galls can vary from small growths on branch extremities to grapefruit-sized galls on trunks.
Hypoxylon canker of shade trees is a weak ascomycete fungus that negatively affects growth and can eventually lead to the death of weak or diseased host trees. There are many different species that affect different trees. For example, Hypoxylon atropunctatum, a common species, is found on oak trees, Hypoxylon tinctor affects sycamore trees, and Hypoxylon mammatum infests aspen trees.
Gnomoniopsis castaneae is a fungus of the order Diaporthales that is the most important cause of brown chestnut rot, an emerging disease that damages the fruit of chestnuts. It also causes cankers and necrosis on leaves and on chestnut galls caused by the gall wasp, Dryocosmus kuriphilus. Additionally, it can cause cankers on other chestnut species, red oak, hazelnut trees, less severe damage to some nut trees, and lives as an endophyte on other nut trees. The disease has been reported in Europe, Oceania, and has recently been found in North America; for this reason, the fungus is considered a potential threat to the reintroduction of the American chestnut.
