Septoria carvi

Septoria carvi

Profile

Septoriosis of caraway is caused by the fungal pathogen Septoria carvi . Occurrence is recognizable by brownish spots on the leaves and stems of the plants. Infestation leads to yield losses of between 30 and 40 %.

Damage symptoms

As symptoms, initially yellowish, then brownish to dark brown, roundish spots, usually 1 mm in diameter, become visible on both sides of the leaf, which rapidly spread and partially merge. On these spots, the fruiting bodies (pycnidia) of the fungus are formed on the upper and lower sides of the leaves, which are difficult to see with the naked eye due to their small size. On the stems the spots are elongated. Again, you need at least a magnifying glass to clearly see the pycnidia. On the partial fruits, which shrink somewhat when infested, small brown spots with pycnidia can be seen, especially with a magnifying glass.

Host plants

Septoriosis of caraway currently occurs only on caraway(Carum carvi).

Distribution

Septoria carvi is relatively common on caraway in Europe (confirmed reports from Germany, Poland, Austria, and the Czech Republic).

Propagation and transmission

The spores (conidia) of the fungus are spread by splashing water droplets. Infections occur through the stomata or by direct penetration of plant tissue. The fungus survives on infected plant debris in the soil and on seeds.

Economic importance

In drier and warmer areas of Austria, infestation is generally lower than in cooler and wetter areas. Infested fruits become not ripe and do not form a full grain. There may be yield losses of between 30 and 40%.

Prevention and control

  • Use of healthy seeds (possibly seed testing).
  • Adherence to a crop rotation of at least five years
  • Carry out infestation control in the stands and, if necessary, carry out treatment with plant protection products (see list of plant protection products approved in Austria)

Last updated: 17.01.2022

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