Question

Observe the figure and answer the following questions.

a) Write the name of the disease
b) Name the causative agent of this disease
c) How does the disease spread from one plant to another?
d) Name any two plant diseases and the microbes that cause them.

Answer 1

a) Citrus Canker
b) The causative agent of citrus canker is the bacterium Xanthomonas citri subsp. citri.
c) The disease primarily spreads through rain, wind-driven rain, and movement of contaminated plant material.
d) Two examples of plant diseases and their causative agents are:
1. Potato Late Blight - caused by the oomycete pathogen Phytophthora infestans.
2. Wheat Rust - caused by various species of the rust fungi, such as Puccinia graminis.

Answer 2

A. Citrus Canker

B. citrus greening is the most serious citrus disease caused by a bacteria that is spread by the Asian citrus psyllid (ACP). ACP is a tiny insect that transmits the bacteria to the tree when feeding.

C. Citrus canker is most severe in hot, wet areas. The infected sites ooze sap which can carry the disease from tree to tree by irrigation or rain splash. Citrus canker can spread quickly over long distances on infected citrus fruits and leaves, as well as on people and equipment.

Citrus canker can spread rapidly by wind and rain, landscaping equipment, people's hands or clothing and moving infected plants or plant parts. Fruit infected with these diseases is safe to eat, but usually does not meet quality standards to be sold in a fresh fruit market.

Citrus greening is the most serious citrus disease caused by a bacteria which is spread by the Asian citrus psyllid (ACP). ACP is a tiny insect that transmits the bacteria to the tree when feeding.

D. Examples of plant diseases:

• Citrus canker diseases of citrus which is caused by the bacterium Xanthomonas citri.

• Tobacco mosaic disease which is caused by the virus tobacco mosaic virus.