Take-all

It is an important disease in winter wheat in Western Europe particularly, and is favoured by conditions of intensive production and monoculture.

Early symptoms of the disease include yellowing and stunting, tillering is reduced and plants mature prematurely and often exhibit bleached seed heads.

Chemical control measures have traditionally had little success, although a modern seed treatment shows promise.

Experiments performed on the famous "Broadbalk" field at Rothamsted Research where continuous monoculture winter wheat is grown, show that take-all build-up (TAB) occurs in successive crops to reach a peak in the 3rd to 5th cropping year, after which the disease declines (TAD), ultimately restoring yields to 80 to 90% of 1st and 2nd year levels.

[5][6] The genetic mechanism of the Low-TAB is still unknown, but the low TAB can still be exploited by farmers, making short wheat rotations more profitable.

[7] Gaeumannomyces tritici causes disease in the roots, crown, and stem base of wheat, barley, rye, along with several grasses such as Bromegrass, Quackgrass, and Bentgrass.

[8][13] When tillers die due to disease they are white, creating a "white-head" that can be described as a sterile environment that isn’t able to germinate.

[14] Signs include perithecia that are shown in infected root and stem tissues which are black in color.

[15] This blackening of the crown and stem base allow the plant to be easily pulled from the soil with no attached root system.

[8] There have been tested areas in Larslan and Toston, Montana, where two different fungi found in particular soil have reduced the severity of take-all through mycoparasitism.

[19] This pathogen may be considered polycyclic because initial inoculum is by mycelial growth by the resting spores, ascomata.