Disease | Bunt of wheat

  1. Thise smut disease also called stinking smuts of wheat are widely distributed in all wheat growing areas of the world.
  2. They effect plant by destroying the constrent of infected kernels and replacing them with the spores of fungus.
  3. Bunt causes losses in grain yield.

Symptoms -

  1. Affected plants are usually shorter then healthy one.
  2. The colour of the plant may changed to bluish green to greenish green.
  3. The most pronounced symptoms however when the head of infected plants emerged.
  4. Infected kernels are shorter and thicker and greyish brown then normal golden yellow or red.
  5. These are usually full of shoot black, powdery mass of spores, the teliospores that give a distil smell of decay fish.

Causing organisms

  1. The disease caused by Telia carris, Telia foetida and Telia contraversa.
  2. They mycellium is hyaline and during sporulation most cells are transformed into sperical, brownish teliospore.
  3. Open the germination each spore produces 8 to 16 cells.
  4. These fuse in pairs forming 'H'  shaped structures.
  5. Each secondary sporedium open germination produces dikaryotic Mycelium that infects the plants.
  6. After systematic development through the plant. The Mycelium again forms teliospores.
  7. The fungus survives as teliospores on contaminated wheat kernels and in soil.
  8. When contaminated seed in shown teliospores germinate with the young seedings and form basidia primary sporedia and secondary sporedia.
  9. The dikaryotic Mycelium formed after germination of Secondary sporedia, penitrate of the young seedlings directly.
  10. It grows interactly and invoices developing leaves and growing point of the plant.
  11. The Mycelium grows with these growing points when heads are form on plant the Mycelium invade all part of it even before the head emerge out of the boot.
  12. These spores are covered by pericarp or the kernels forming a covering around the spore mass.
  13. They break and release their spore during harvest or thorting.

Controls -

  1. Use of resisted variety.
  2. Sanitation that is burning of straw and other infected part.
  3. Crop rotation to avoid infection by soil borne teliospore.
  4. Cultural practices that is modification of soil temperature and motiour.
  5. Seed treatment to aliminate seed born teliospore.
  6. Hexa chlorobenzene (carboxine) Thiram, Chloranil.