Covered smut | |
---|---|
![]() | |
Result of covered smut on oat (1) and barley (2), illustration published in M. Cilenšek: Naše škodljive rastline (1892) | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Basidiomycota |
Class: | Ustilaginomycetes |
Order: | Ustilaginales |
Family: | Ustilaginaceae |
Genus: | Ustilago |
Species: | U. hordei |
Binomial name | |
Ustilago hordei (Pers.) Lagerh. | |
Covered smut of barley is caused by the fungus Ustilago hordei. The disease is found worldwide and it is more extensively distributed than either loose smut or false loose smut. [1] [2]
Infected plants do not demonstrate symptoms until heading. Kernels of infected plants are replaced by masses of dark brown smut spores. Smutted heads are hard and compact. Infected plants may be stunted. Occasionally smut sori may also develop in leaf blades, where they appear as long streaks.
Infection is seed-borne within the seed, the fungus penetrating the endosperm while the grain is being formed. Infected seeds give rise to systemically infected plants. The mycelium advances through the host tissue and becomes established behind the growing point.
The spores are not readily blown or washed away by wind or rain. Spores are sticky in nature when present inside the membrane due to oily coating. At harvest, spore masses are broken up, scattering spores on grain. Frequently, masses of spores remain intact and appear in harvested grain. The fungus overwinters as teliospores on seed or in soil.
At least 13 pathotypes are known; virulence is governed by at least three single recessive and independent gene pairs.
Resistant cultivars and seed treatments are used to manage this disease.
Seed treatments: carboxin, fenpiclonil, tebuconazole, triadimenol, triticonazole.
The smuts are multicellular fungi characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled, and dust-like teliospores. They are mostly Ustilaginomycetes and can cause plant disease. The smuts are grouped with the other basidiomycetes because of their commonalities concerning sexual reproduction.
Scald is common disease of barley in temperate regions. It is caused by the fungus Rhynchosporium commune and can cause significant yield losses in cooler, wet seasons.
Common bunt, also known as hill bunt, Indian bunt European bunt, stinking smut or covered smut, is a disease of both spring and winter wheats. It is caused by two very closely related fungi, Tilletia tritici and T. laevis.
Spot blotch is a disease of barley caused by Cochliobolus sativus. The disease is found everywhere that barley is grown, but only causes significant yield losses in warm, humid climates.
Loose smut of barley is caused by Ustilago nuda. It is a disease that can destroy a large proportion of a barley crop. Loose smut replaces grain heads with smut, or masses of spores which infect the open flowers of healthy plants and grow into the seed, without showing any symptoms. Seeds appear healthy and only when they reach maturity the following season is it clear that they were infected. Systemic fungicides are the major control method for loose smut.
False loose smut is a fungal disease of barley caused by Ustilago nigra. This fungus is very similar to U. nuda, the cause of loose smut, and was first distinguished from it in 1932.
Common root rot is a fungal disease of barley caused by Cochliobolus sativus, Fusarium culmorum and F. graminearum.
Powdery mildew is a fungal disease of barley caused by Blumeria graminis f. sp. hordei. The disease has a worldwide distribution and is most damaging in cool, wet climates. The host range of the form species hordei is restricted to barley and other Hordeum species.
Fusarium culmorum is a fungal plant pathogen and the causal agent of seedling blight, foot rot, ear blight, stalk rot, common root rot and other diseases of cereals, grasses, and a wide variety of monocots and dicots. In coastal dunegrass, F. culmorum is a nonpathogenic symbiont conferring both salt and drought tolerance to the plant.
Gibberella zeae, also known by the name of its anamorph Fusarium graminearum, is a fungal plant pathogen which causes fusarium head blight (FHB), a devastating disease on wheat and barley. The pathogen is responsible for billions of dollars in economic losses worldwide each year. Infection causes shifts in the amino acid composition of wheat, resulting in shriveled kernels and contaminating the remaining grain with mycotoxins, mainly deoxynivalenol (DON), which inhibits protein biosynthesis; and zearalenone, an estrogenic mycotoxin. These toxins cause vomiting, liver damage, and reproductive defects in livestock, and are harmful to humans through contaminated food. Despite great efforts to find resistance genes against F. graminearum, no completely resistant variety is currently available. Research on the biology of F. graminearum is directed towards gaining insight into more details about the infection process and reveal weak spots in the life cycle of this pathogen to develop fungicides that can protect wheat from scab infection.
Tilletia caries is a basidiomycete that causes common bunt of wheat. The common names of this disease are stinking bunt of wheat and stinking smut of wheat. This pathogen infects wheat, rye, and various other grasses. T. caries is economically and agriculturally important because it reduces both the wheat yield and grain quality.
Urocystis agropyri is a fungal plant pathogen that causes flag smut on wheat.
Ustilago avenae is a plant pathogen. Semiloose smut of oats can be found wherever oats are grown, as they are seldom treated with seed treatments. The level of treatment is low because oats command a lower sale price than other cereals and hence it is thought that treatment is uneconomic. Semiloose smut of oats, unlike loose smut of wheat and barley, can thus infect up to 80 per cent of a crop.
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
Sporisorium sorghi, commonly known as sorghum smut, is a plant pathogen that belongs to the Ustilaginaceae family. This fungus is the causative agent of covered kernel smut disease and infects sorghum plants all around the world such as Sorghum bicolor (sorghum), S. sudanense, S. halepense and Sorghumvulgare var. technichum (broomcorn). Ineffective control of S. sorghi can have serious economic and ecological implications.
Ustilaginoidea virens, perfect sexual stage Villosiclava virens, is a plant pathogen which causes the disease "false smut" of rice which reduces both grain yield and grain quality. The disease occurs in more than 40 countries, especially in the rice producing countries of Asia. but also in the U.S. As the common name suggests, it is not a true smut (fungus), but an ascomycete. False smut does not replace all or part of the kernel with a mass of black spores, rather sori form erupting through the palea and lemma forming a ball of mycelia, the outermost layers are spore-producing. Infected rice kernels are always destroyed by the disease.
Sporisorium reilianum Langdon & Full., (1978), previously known as Sphacelotheca reiliana, and Sporisorium reilianum, is a species of biotrophic fungus in the family Ustilaginaceae. It is a plant pathogen that infects maize and sorghum.
Gibberella fujikuroi is a fungal plant pathogen. It causes bakanae disease in rice seedlings.
This article summarizes different crops, what common fungal problems they have, and how fungicide should be used in order to mitigate damage and crop loss. This page also covers how specific fungal infections affect crops present in the United States.
Ustilago esculenta is a species of fungus in the Ustilaginaceae, a family of smut fungi. It is in the same genus as the fungi that cause corn smut, loose smut of barley, false loose smut, covered smut of barley, loose smut of oats, and other grass diseases. This species is pathogenic as well, attacking Manchurian wild rice, also known as Manchurian ricegrass, Asian wild rice, and wateroat. This grass is its only known host.