Question

Which crop is associated with a disease called red rot?

Answer 1

Hint: The red rot disease is one of the deadliest diseases and is known to have been described from Java by Went in the year 1893. The name ‘red rot’ was given by Sir E.J. Butler who was a mycologist from India in 1906.

Complete answer:
The red rot disease affects sugarcane crop and is caused by the fungus Glomerella tucumanensis. The first symptoms of the disease involve withering, drooping and ultimately yellowing of the upper leaves which is followed by drooping of the crown and ultimately the entire plant shows symptoms and dies.

The infection is mostly in the stem and internal, only when the stem is cut is found that the protoplasm has changed colour and a gummy dark red material is seen to be oozing out of the cells that fill the intercellular spaces. The ooze consists of a soluble pigment that is absorbed by the cell wall leading to the development of the characteristic red rot appearance.

With the advancement of the disease, the red colour spreads to the surrounding tissues reaching through internodes and many reddish or white with red margins blotches are seen to develop. When the stem is completely rotted black specks are found to appear and the stem gives out a foul smell.

Note: Thus red rot disease being highly harmful should be controlled so that sugarcane crops are not destroyed as they have high commercial value. To prevent red rot seeds should be taken from disease-free nurseries and carefully examined before they are grown. Those seeds that show little reddening should be discarded immediately.