Disease Control
Overview
Crop diseases are caused by tiny living things you cannot see without a microscope: bacteria, fungi and viruses. A single infected plant left in a field can become the source that spreads disease to a whole crop, turning a healthy harvest into a failure. Knowing what causes a disease, how it gets into the plant and how it spreads is the key to stopping it.
In this lesson you will study one named disease from each group: a bacterial disease, a fungal disease and a viral disease. For each you will learn how it infects the plant, the harm it does, and how it can be prevented and controlled. You will also meet the idea of the disease triangle, which explains why removing any one of three things, the pathogen, a susceptible crop or the right conditions, can stop a disease in its tracks.
Objectives
- (a) describe the mode of infection, harmful effects, prevention and control of one named plant disease from each of the following groups: • bacterial diseases • fungal diseases • viral diseases.
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Disease Control. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which conditions are most likely to encourage fungal diseases? A. Dry and cool B. Dry and warm C. Wet and cool D. Wet and warm Answer: D
- Maize streak virus is spread from plant to plant by: A. Rain splash B. Leafhoppers C. The wind alone D. Contaminated tools Answer: B
- Cassava bacterial blight is caused by a: A. Virus B. Fungus C. Bacterium D. Nematode Answer: C
- The most effective way to control a viral disease of a crop is usually to: A. Spray a fungicide B. Grow resistant varieties and control the insect carrier C. Add more fertiliser D. Water the crop more often Answer: B
- Which practice helps control a fungal disease by keeping the crop drier? A. Closer spacing of plants B. Flooding the field C. Wider spacing and good drainage D. Leaving infected plants in place Answer: C
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Recommended Books
Practice Mock Questions
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