Take-all
Encyclopedia
Take-all is a plant disease affecting the roots of cereal plants in temperate climates caused by the fungus Gaeumannomyces graminis var. tritici. All varieties of wheat
and barley
are susceptible. It is an important disease in winter wheat
in Western Europe particularly, and is favoured by conditions of intensive production and monoculture
.
growing through the soil which is why the disease is often seen in patches. The fungus blocks the conductive tissue
of the plants and reduces water uptake. Early signs of the disease include yellowing and stunting, tillering is reduced and plants mature prematurely and often exhibit bleached seed heads. The affected roots are blackened and the plants are easy to pull from the soil. These symptoms give rise to an alternative name for the disease, "whiteheads". Yield loss levels of 40 to 50 % are often recorded in severe attacks.
. This can limit damage from the disease.
The most appropriate control measure is the use of a clean one-year break crop
of a non-cereal crop. This reduces the fungus to an acceptably low soil contamination
level in about 10 months although the existence of volunteer grasses may reduce any beneficial effects.
There exists a phenomenon known as "take-all decline". Experiments performed on the famous "Broadbalk" field at Rothamsted Experimental Station
where continuous monoculture winter wheat is grown, show that take-all build-up occurs in successive crops to reach a peak in the 3rd to 5th cropping year, after which the disease declines, ultimately restoring yields to 80 to 90 % of 1st and 2nd year levels. The decline cycle is destroyed by the introduction of a crop other than wheat or barley.
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
and barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
are susceptible. It is an important disease in winter wheat
Winter wheat
Winter wheat is a type of wheat that is planted from September to December in the Northern Hemisphere. Winter wheat sprouts before freezing occurs, then becomes dormant until the soil warms in the spring. Winter wheat needs a few weeks of cold before being able to flower, however persistent snow...
in Western Europe particularly, and is favoured by conditions of intensive production and monoculture
Monoculture
Monoculture is the agricultural practice of producing or growing one single crop over a wide area. It is also known as a way of farming practice of growing large stands of a single species. It is widely used in modern industrial agriculture and its implementation has allowed for large harvests from...
.
The disease
The Fungus return to the Class:Pyrenomycetes Order:Diaporthales (Agrios.2005.Plant pathology) . The disease survives in the soil on infected cereal and grass residues. The fungus infects the root tissue of young plants and can spread from plant to plant in the form of hyphaeHypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
growing through the soil which is why the disease is often seen in patches. The fungus blocks the conductive tissue
Xylem
Xylem is one of the two types of transport tissue in vascular plants. . The word xylem is derived from the Classical Greek word ξυλον , meaning "wood"; the best-known xylem tissue is wood, though it is found throughout the plant...
of the plants and reduces water uptake. Early signs of the disease include yellowing and stunting, tillering is reduced and plants mature prematurely and often exhibit bleached seed heads. The affected roots are blackened and the plants are easy to pull from the soil. These symptoms give rise to an alternative name for the disease, "whiteheads". Yield loss levels of 40 to 50 % are often recorded in severe attacks.
Control
Chemical control measures have traditionally had little success, although a modern seed treatment shows promise. Crop nutrition imbalances exacerbate the disease, as does excessive liming. Modern varieties are stiff and short-strawed which allows relatively high spring nitrogen applications without serious lodgingLodging
Lodging is a type of residential accommodation. People who travel and stay away from home for more than a day need lodging for sleep, rest, safety, shelter from cold temperatures or rain, storage of luggage and access to common household functions.Lodgings may be self catering in which case no...
. This can limit damage from the disease.
The most appropriate control measure is the use of a clean one-year break crop
Break crop
Break crop is a term for the secondary crop within the practice of sustainable agriculture with intensive arable farming whereby as part of a crop rotation, a physiologically different crop is inserted into the main cropping plan in order to provide a "break" from the cycle of weeds, pests and...
of a non-cereal crop. This reduces the fungus to an acceptably low soil contamination
Soil contamination
Soil contamination or soil pollution is caused by the presence of xenobiotic chemicals or other alteration in the natural soil environment....
level in about 10 months although the existence of volunteer grasses may reduce any beneficial effects.
There exists a phenomenon known as "take-all decline". Experiments performed on the famous "Broadbalk" field at Rothamsted Experimental Station
Rothamsted Experimental Station
The Rothamsted Experimental Station, one of the oldest agricultural research institutions in the world, is located at Harpenden in Hertfordshire, England. It is now known as Rothamsted Research...
where continuous monoculture winter wheat is grown, show that take-all build-up occurs in successive crops to reach a peak in the 3rd to 5th cropping year, after which the disease declines, ultimately restoring yields to 80 to 90 % of 1st and 2nd year levels. The decline cycle is destroyed by the introduction of a crop other than wheat or barley.