Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" or "gray mold".
Uncinula necator is a fungus that causes powdery mildew of grape. It is a common pathogen of Vitis species, including the wine grape, Vitis vinifera. The fungus is believed to have originated in North America. European varieties of Vitis vinifera are more or less susceptible to this fungus. Uncinula necator infects all green tissue on the grapevine, including leaves and young berries. It can cause crop loss and poor wine quality if untreated. The sexual stage of this pathogen requires free moisture to release ascospores from its cleistothecia in the spring. However, free moisture is not needed for secondary spread via conidia; high atmospheric humidity is sufficient. Its anamorph is called Oidium tuckeri.
Pyrenophora teres is a necrotrophic fungal pathogen of some plant species, the most significant of which are economically important agricultural crops such as barley. Toxins include aspergillomarasmine A and related compounds.
Venturia inaequalis is an ascomycete fungus that causes the apple scab disease.
Monilinia laxa is a plant pathogen that is the causal agent of brown rot of stone fruits.
Leveillula taurica is an obligate fungal pathogen, from the phylum Ascomycota, which causes powdery mildew on onion. This disease prefers warm, dry environments. It is rare in the United States, and is currently restricted to western states. Globally, it is also a minor problem with limited occurrences in the Middle East, Europe, and South America. L. taurica causes powdery mildew of onions, but is also known to infect other allium, solanaceous, and cucurbit species. The disease has appeared in parts of the Middle East, the Mediterranean, and South and North America. Currently, it is not a cause for major concern in the U.S. and throughout the world, as its geographic extent is sparse. In addition, it is relatively easy to control through basic sanitation and reducing water stress.
Stemphylium solani is a plant pathogen fungus in the phylum Ascomycota. It is the causal pathogen for grey leaf spot in tomatoes and leaf blight in alliums and cotton, though a wide range of additional species can serve as hosts. Symptoms include white spots on leaves and stems that progress to sunken red or purple lesions and finally leaf necrosis. S. solani reproduces and spreads through the formation of conidia on conidiophores. The teleomorph name of Stemphyllium is Pleospora though there are no naturally known occurrences of sexual reproduction. Resistant varieties of tomato and cotton are common, though the pathogen remains an important disease in Chinese garlic cultivation.
Diplocarpon earlianum is a species of fungus that causes disease in strawberry plants called strawberry leaf scorch. The disease overwinters in plant debris and infects strawberry plants during the spring season when it is wet. The five main methods to reduce strawberry leaf scorch include: irrigation techniques, crop rotation, planting resistant and disease-free seeds, fungicide use, and sanitation measures. Control of strawberry leaf scorch is important because it is responsible for the majority of disease in strawberries. Diplocarpon earliana affects the fruit quality and yield of the strawberry crop. Losses range from negligible to severe depending on numerous epidemiological factors including cultivar susceptibility, type of cropping system, and weather conditions
Ascochyta is a genus of ascomycete fungi, containing several species that are pathogenic to plants, particularly cereal crops. The taxonomy of this genus is still incomplete. The genus was first described in 1830 by Marie-Anne Libert, who regarded the spores as minute asci and the cell contents as spherical spores. Numerous revisions to the members of the genus and its description were made for the next several years. Species that are plant pathogenic on cereals include, A. hordei, A. graminea, A. sorghi, A. tritici. Symptoms are usually elliptical spots that are initially chlorotic and later become a necrotic brown. Management includes fungicide applications and sanitation of diseased plant tissue debris.
Oidium mangiferae is a plant pathogen that infects mango trees causing powdery mildew. Powdery mildew of mango is an Ascomycete pathogen of the Erysiphales family that was initially described by Berthet in 1914, using samples collected from Brazil. O. mangiferae is found in all areas where mangoes have been raised long term, but is particularly widespread in India where both the host and the pathogen are native. Currently no teleomorph stage has been identified, but due to certain morphological characteristics it has been suggested that O. mangiferae belongs in the Erysiphe polygony group. Mango is the only known host for this pathogen, though O. mangiferae appears to be identical to fungi responsible for powdery mildew diseases on various other plant species, particularly oak, though some differences may be observed. In particular, the number of cells in conidiophores varies from 2 on mango to 3-5 on oak. O. mangiferae has been known to infect oak leaves in the laboratory, however due to the lack of a known teleomorph stage O. mangiferae is still considered to only be a pathogen of mango. Recent analysis of its ribosomal DNA suggests it is conspecific with Erysiphe alphitoides, the causative agent of powdery mildew in European oaks.
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.
Botrytis fabae is a plant pathogen, a fungus that causes chocolate spot disease of broad or fava bean plants, Vicia faba. It was described scientifically by Mexican-born Galician microbiologist Juan Rodríguez Sardiña in 1929.
Rhytisma acerinum is a plant pathogen that commonly affects sycamores and maples in late summer and autumn, causing tar spot. Tar spot does not usually have an adverse effect on the trees' long-term health. R. acerinum is an Ascomycete fungus that locally infects the leaves of trees and is a biotrophic parasite. The disease is cosmetic and is therefore usually controlled only with sanitation methods.
Ascochyta blights occur throughout the world and can be of significant economic importance. Three fungi contribute to the ascochyta blight disease complex of pea. Ascochyta pinodes causes Mycosphaerella blight. Ascochyta pinodella causes Ascochyta foot rot, and Ascochyta pisi causes Ascochyta blight and pod spot. Of the three fungi, Ascochyta pinodes is of the most importance. These diseases are conducive under wet and humid conditions and can cause a yield loss of up to fifty percent if left uncontrolled. The best method to control ascochyta blights of pea is to reduce the amount of primary inoculum through sanitation, crop-rotation, and altering the sowing date. Other methods—chemical control, biological control, and development of resistant varieties—may also be used to effectively control ascochyta diseases.
Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen Bipolaris maydis.
Common spot of strawberry is one of the most common and widespread diseases afflicting the strawberry. Common spot of strawberry is caused by the fungus Mycosphaerella fragariae. Symptoms of this disease first appear as circular, dark purple spots on the leaf surface. Mycosphaerella fragariae is very host-specific and only infects strawberry.
Gummy stem blight is a cucurbit-rot disease caused by the fungal plant pathogen Didymella bryoniae. Gummy stem blight can affect a host at any stage of growth in its development and affects all parts of the host including leaves, stems and fruits. Symptoms generally consist of circular dark tan lesions that blight the leaf, water soaked leaves, stem cankers, and gummy brown ooze that exudes from cankers, giving it the name gummy stem blight. Gummy stem blight reduces yields of edible cucurbits by devastating the vines and leaves and rotting the fruits. There are various methods to control gummy stem blight, including use of treated seed, crop rotation, using preventative fungicides, eradication of diseased material, and deep plowing previous debris.
Gray leaf spot (GLS) is a foliar fungal disease that affects grasses. In grasses other than maize it is caused by Pyricularia grisea, which only infects perennial ryegrass, tall fescue, and St. Augustine grass in places with warm and rainy climates.
Botrytis squamosa is a fungus that causes leaf blight on onion that is distinctly characterized by the two stages – leaf spotting followed by blighting. The pathogen is an ascomycete that belongs to the family Sclerotiniaceae in the order Helotiales. The lesions start out as whitish streaks and take on a yellow tinge as they mature. They cause yield losses up to 30%. This fungus is endemic to the USA and has also been reported in Europe, Asia, and Australia. Typical management of this disease includes chemical fungicides with significant efforts being made to establish a means of biological control.
Alternaria brassicicola is a fungal necrotrophic plant pathogen that causes black spot disease on a wide range of hosts, particularly in the genus of Brassica, including a number of economically important crops such as cabbage, Chinese cabbage, cauliflower, oilseeds, broccoli and canola. Although mainly known as a significant plant pathogen, it also contributes to various respiratory allergic conditions such as asthma and rhinoconjunctivitis. Despite the presence of mating genes, no sexual reproductive stage has been reported for this fungus. In terms of geography, it is most likely to be found in tropical and sub-tropical regions, but also in places with high rain and humidity such as Poland. It has also been found in Taiwan and Israel. Its main mode of propagation is vegetative. The resulting conidia reside in the soil, air and water. These spores are extremely resilient and can overwinter on crop debris and overwintering herbaceous plants.
