IFS (Forest Services) Agriculture: Questions 1 of 646
Appeared in Year: 2015
Describe in Detail Subjective▾
Write short notes on the following: Tundu disease of wheat (Paper-1, Section-A)
EditExplanation
Tundu Disease of Wheat
- Tundu disease of wheat is also called as yellow Ear rot or Ear cockle.
- Tundu is a minor disease problem worldwide.
- It is quite common in north-west regions of India.
- This disease of wheat was first reported by Hutchinson in 1917 from Punjab.
- Now it is spread in many other parts of the country like Haryana, U. P. , Rajasthan, M. P. and Bihar.
- This disease is also common in Canada, China, Australia and Egypt.
Pathogen or Causal Organism
- Tundu disease is caused by bacterium Corynebacterium tritici.
- It is gram-positive bacteria, rod shaped with single polar flagellum.
- Tundu disease is actually caused by the combined action of bacterium Corynebacterium tritici and nematode Anguina tritici.
- The galls in the ear heads are formed by the nematodes and these galls carry the bacterium.
Symptoms
- The early symptoms include twisting of stem and distortion of spikelets or ear heads.
- Yellow exudate on the spikes is indicative of bacterial diseases.
- When it is dry, the exudate is white to yellow white.
- The spikes and necks will emerge as a distorted sticky.
- The early leaves may also be wrinkled or twisted.
- Most of the grains in the ear heads are replaced by galls and these galls contain the causal bacterium Corynebacterium tritici.
Spread
- Seeds are contaminated with nematode galls which are responsible for the spread of the disease.
How to Control
- Use of seeds which are free from nematode galls or use certified seeds.
- Nematode galls can be removed by sieving or flotation in 5% salt solution and washing thoroughly in plain water and drying the seed before sowing.
- Hot-water treatment of contaminated wheat seed is also effective in the removal of nematode galls from seed lots.
- In 1938, Jones et al. developed an indented cylinder machine which separated oval wheat seeds from globular nematode galls and this device was claimed to be 98% effective in removing seed galls.
- In 1945, Chu also designed a machine to separate nematode galls from healthy grain.