Pyrenophora tritici-repentis

Pyrenophora tritici - repentis, also known by its anamorph Drechslera tritici - repentis, is a fungus from the order of Pleosporales, which causes the plant disease DTR leaf spot, especially for wheat. The reduction in yield of the crop may be through reduction of photosynthesis up to 30 %.

Features

The fungus grows on various grasses and cereals. An important distinguishing feature is considered the conical, snake head-shaped basal cell of the conidia. These are straight or slightly curved, cylindrical and rounded apically. They are straw-colored, have 5-6 septa and are 80-250 × 14-20 microns in size. Sporulation occurs in a humid chamber (similar to Drechslera teres, the causal agent of net blotch of barley).

Disease

On ground level is roundish leaves, uniformly light brown colored spots form. Secondary infections fall on its dark brown points infection diameter of about 3 mm, surrounded by a yellow halo. These leaf spots coalesce over time and cause an outgoing from the top leaf blotch.

Infestation Supporting factors

Infected crop residues on the soil surface, as they occur frequently in mulch, and infected seed are conducive to the fungus. In addition, stress factors such as lack of water or occasional rainfall can promote the spread.

Swell

• Horst Börner, Klaus Schlüter, Jens Aumann: The major diseases and pests of field, vegetable and fruit crops with an indication of the main symptoms. Springer, Berlin Heidelberg 2009, ISBN 978-3-540-49067-8