Question

Citrus canker is caused by
A. Bacterium
B. Fungus
C. Algae
D. Virus

Answer 1

Hint: The Citrus canker is a disease of the plants. It usually affects all the citrus plants including orange, lemon, etc. the characteristics of citrus canker are the lesions on leaves, stems, and fruits majorly. The affected plant’s fruits will fall prematurely. Although the fruits infected with citrus canker are safe to eat their appearance is unsightly to be sold. It is caused by bacterial species when the spores of bacteria enter through the wounds on the plant or by stomata.

Complete step by step answer: The citrus canker is an issue of major interest in Brazil and the US. Once it enters the field it is very persistent and difficult to remove. It is caused by a gram-negative bacteria named Xanthomonas citri. It is rod-shaped, flagellated motile bacteria that enter through the stomata of the leaves and infects the whole plant persistently. It can enter the plant by wounds or cuts on stems. The characteristics of the infection include blister-like lesions on leaves and fruits. These blisters can turn leaves and fruits black or brown over time. The circular lesions usually are covered with yellowish borders. The lesions oozed the bacterial cells out of them. These bacterial cells are then spread in the whole field with the help of wind or contaminated utensils. The leaves and stems of the plants are most susceptible to infection within the six initial weeks of growth. The bacteria produce multiple lesions of different ages by multiple infection cycles.
So, it is the bacteria that cause the Citrus canker. Therefore, the right option is option A.

Note: The management of Citrus canker involves proper sanitation and quarantine measures. The citrus plants are kept away from the main fields. Proper sanitation practices are followed to avoid contact of instruments with any infected plant. Once the disease enters the fields it is very difficult to eradicate it. Usually, all the plants carrying the disease are uprooted or burned to prevent further infection.