A plant canker is a small area of dead tissue, which grows slowly, often over years. Some cankers are of only minor consequence, but others are ultimately lethal and therefore can have major economic implications for agriculture and horticulture. Their causes include a wide range of organisms as fungi, bacteria, mycoplasmas and viruses. The majority of canker-causing organisms are bound to a unique host species or genus, but a few will attack other plants. Weather and animal damage can also cause stress to the plant resulting in cankers. Other causes of cankers is pruning when the bark is wet or using un-sterilized tools.
Glomerella graminicola is an economically important crop parasite affecting both wheat and maize where it causes the plant disease Anthracnose Leaf Blight.
Colletotrichum acutatum is a plant pathogen and endophyte. It is the organism that causes the most destructive fungal disease, anthracnose, of lupin species worldwide. It also causes the disease postbloom fruit drop on many varieties of citrus, especially Valencia and navel oranges in Florida.
Cadophora malorum is a saprophytic plant pathogen that causes side rot in apple and pear and can also cause disease on asparagus and kiwifruit. C. malorum has been found parasitizing shrimp and other fungal species in the extreme environments of the Mid-Atlantic Ridge, and can be categorized as a halophilic psychrotrophic fungus and a marine fungus.
Fusarium redolens is a species of fungus in the genus Fusarium and family Nectriaceae. This species is a soil-borne plant pathogen in temperate prairies. It causes diseases such as root, crown, and spear rot, seedling damping-off, and wilting disease. It is a known producer of the alkaloids peimisine and imperialine-3β-d-glucoside, which has implications for traditional Chinese medicine.
Colletotrichum capsici is a species of fungus and plant pathogen which causes leaf blight on Chlorophytum borivilianum, basil, chickpea and pepper as well as dieback in pigeonpea and anthracnose in poinsettia.
Glomerella cingulata is a fungal plant pathogen, being the name of the sexual stage (teleomorph) while the more commonly referred to asexual stage (anamorph) is called Colletotrichum gloeosporioides. For most of this article the pathogen will be referred to as C. gloeosporioides. This pathogen is a significant problem worldwide, causing anthracnose and fruit rotting diseases on hundreds of economically important hosts.
Monilinia fructigena is a plant pathogen in the fungus kingdom causing a fruit rot of apples, pears, plums, peaches and cherries.
Colletotrichum fragariae is a fungal plant pathogen infecting strawberries. It is not a well known fungus, and there are many similar fungi that are related to it. It is part of the Colletotrichum genus. It is a pathogen that occurs in strawberries. It leads to the disease known as anthracnose. This is typically at the crown of the strawberry, which is why it is often called crown rot. It is also known as the Anthracnose Crown rot. The fungus also infects leaves and is known as leaf spot, which is common among all Colletotrichum. This is not as common in the fragariae, as it is more common in the crown. This fungus is also better at infecting younger strawberries/seedlings. The most common way to control this disease is fungicides that are harmful to the environment. There have been studies done to see if the fungus infects other hosts but other than some weeds, it is very specific to Strawberries.
Diaporthe phaseolorum var. caulivora is a fungal plant pathogen which infects soybean, causing soybean stem canker.
Pecan anthracnose is a fungal disease of pecan trees caused by the ascomycete Glomerella cingulata (Stoneman) Spauld. & H. It is a widespread disease found wherever pecan trees are grown. Pecan anthracnose has been reported as far back in time as 1914, and as far away as Argentina. Glomerella cingulata has two anamorphs which cause disease on pecan trees, Colletotrichum gloeosporioides and Colletotrichum acutatum. The occurrence of Colletotrichum on pecans has contributed to a significant decline in pecan production in various years. An increase in the incidence of pecan anthracnose is highly correlated with heavy rainfall, especially heavy rainfall occurring in early spring. The severity of symptoms increases as the season progresses, often culminating in leaf drop in the late autumn. This defoliation is linked to lower yield and poorer quality of nuts.
Fusarium mangiferae is a fungal plant pathogen that infects mango trees. Its aerial mycelium is white and floccose. Conidiophores on aerial mycelium originating erect and prostrate from substrate; they are sympodially branched bearing mono and polyphialides. Polyphialides have 2–5 conidiogenous openings. Phialides on the aerial conidiophores mono- and polyphialidic. Sterile hyphae are absent. Microconidia are variable in shape, obovoid conidia are the most abundant type, oval to allantoid conidia occurring occasionally. Microconidia mostly 0-septate with 1-septate conidia occurring less abundantly. Sporodochia are present. Macroconidia are long and slender, usually 3–5 septate. Chlamydospores are absent.
Verticillium nonalfalfae is a soilborne fungus in the order Hypocreales. It causes verticillium wilt in some plant species, particularly Ailanthus altissima. The fungus produces a resting mycelium characterized by brown-pigmented hyphae. It is most closely related to V. dahliae and V. alfalfae.
Hemibiotrophs are the spectrum of plant pathogens, including bacteria, oomycete and a group of plant pathogenic fungi that keep its host alive while establishing itself within the host tissue, taking up the nutrients with brief biotrophic-like phase. It then, in later stages of infection switches to a necrotrophic life-style, where it rampantly kills the host cells, deriving its nutrients from the dead tissues.
Bitter rot of apple is a fungal disease of apple fruit that is caused by several species in the Colletotrichum acutatum and Colletotrichum gloeosporioides species complexes. It is identified by sunken circular lesions with conical intrusions into the apple flesh that appear V-shaped when the apple is cut in half through the center of the lesion. It is one of the most devastating diseases of apple fruit in regions with warm wet weather.
