Covered smut
From Wikipedia, the free encyclopedia
Tilletia caries
Also known as "bunt" or "stinking smut", this was a serious disease of wheat in Europe before the invention of organomercury seed disinfectants.
[edit] Symptoms
Black, fishy-smelling spores colonise the developing grains, turning them into bags of fungus known as "bunt balls" or "butts". All of the grains in the ear and all ears derived from an infected seed are infected. During harvest threshing operations, the "bunt balls" burst, releasing the spores onto the healthy grain. Infected crops are unfit for milling. Worse, all harvest, transport and storage equipment is contaminated, leading to more contamination of healthy grain. Infection only becomes apparent prior to harvest since an infected ear develops in the same way as a healthy one although plants may be shorter.
The spores on the outside of the grain infect the young shoot following germination and from then on the mycelium of the fungus develops just behind the growing tip of the plant until ear emergence.
[edit] Control
Some degree of varietal resistance occurs but thanks to organomercury dressings and other more modern products the disease is now practically unknown in commercial crops.
