Disease control：练习题

How does a contagious disease differ from a general infectious disease in livestock management?

Why are certain livestock diseases classified by agricultural authorities as notifiable (scheduled) diseases?

Name one specific bacterial disease in plants and suggest one method of prevention used to limit its spread.

Describe the mode of infection for a named fungal disease in crops and suggest two cultural methods to limit its spread.

Compare the mode of infection and harmful effects of a named fungal disease with those of a named viral disease in a specific crop.

(a) State the name of one bacterial disease that affects crops and describe its mode of infection.
(b) List two harmful effects of this disease on the growth or yield of the plant.

Viral diseases can cause significant economic losses in agriculture.
(a) Explain how viral diseases are typically spread between plants in a field.
(b) Describe two methods used to prevent the introduction or spread of viral diseases, as they cannot be cured with chemical sprays once the plant is infected.