Question

Citrus canker is caused by……
A. Bacteria
B. Virus
C. Fungus
D. Alga

Answer 1

Citrus canker is a plant disease that affects citrus species by making their fruit and leaves drop before ripening. It has first emerged in Southeast Asia.

Complete Answer:
- Citrus canker is a disease that only affects plants, significantly citrus species. It is not harmful to humans. It gives rise to lesions on stems, fruit, and leaves of trees such as oranges, lime, etc. It causes fall off fruits and leaves prematurely and affects the life of citrus species.
- It can be dangerous under some particular climatic conditions such as warm weather and rain at the initial period of fruit development. This disease started leaving dark patches and spots of lesions on fruits, stems, and leaves. Initially, these patches are small, and then start growing into big patches.
- After the pathogen multiplying profusely, it becomes an ideal source of contamination. Pathogen starts penetrating inside the tree from stomata or open wounds and affects the young and developing parts of the tree.
- So, it is a serious disease which is caused by a bacterium named Xanthomonas axonopodis citri. It is a gram-negative bacterium that is slender and rod-shaped. Various type of canker disease caused in citrus trees by different variants of bacterium such as canker A is Asiatic type, Cancrosis B found in South America that caused in lemons, Cancrosis C which affects only bitter orange and key lime, and A type of strain also only affects key lime found in the middle-east.
- Windbreaks are profoundly successful in lessening the spread of blisters, yet more critically, they lessen the seriousness of the contamination in endemic circumstances. At the point when blister sores are wetted, a great many microorganisms overflow onto the leaf surface.
- While microorganisms can swim short separations, they have no dynamic way to infiltrate the natural product, leaves, or twigs. By far most of the contamination happens by wind-blown downpours. Winds of 18-20 mph are expected to compel microorganisms into the stomata on leaves and natural products.

So, the correct answer is A ‘Bacteria’.

Note: Now, we know that citrus canker is caused by bacteria Xanthomonas axonopodis citri that affects citrus trees and plants on the leaves, stem, and fruits by giving rise to lesions and dropping of fruits and leaves prematurely. This bacterium affects the citrus type of plants.