Protection from Diseases MCQs Quiz | Class 9

This quiz is designed for Class IX Science (Code 086) students studying Unit IV: Food Production. It focuses on the topic “Protection from Diseases,” covering plant disease prevention and management basics. Test your understanding of how to protect crops from pathogens and pests. Submit your answers to view your score and download the PDF answer sheet for revision.

Understanding Plant Disease Protection

In Unit IV: Food Production, protecting crops from biotic and abiotic stresses is crucial for high yields. Crop protection management involves shielding cultivated plants from weeds, insect pests, and diseases.

1. Key Threats to Crops

  • Weeds: Unwanted plants in the cultivated field (e.g., Xanthium, Parthenium) that compete for food, space, and light.
  • Insect Pests: They damage plants by cutting roots/stems/leaves, sucking cell sap, or boring into stems and fruits.
  • Diseases: Caused by pathogens like bacteria, fungi, and viruses. These can be transmitted through soil, water, or air.

2. Methods of Control

Method Description Example
Chemical Control Using synthesized chemicals to kill pests/weeds. Herbicides, Insecticides, Fungicides.
Biological Control Using living organisms to suppress pests. Specific insects that eat weeds.
Cultural Methods Farming practices that reduce pest incidence. Crop rotation, summer ploughing.

3. Preventive Measures

Prevention is better than cure. Effective preventive measures include:

  • Use of Resistant Varieties: Breeding crops that naturally resist specific diseases.
  • Summer Ploughing: Ploughing fields deep in summer to destroy weeds and pests via heat.
  • Seed Treatment: Treating seeds with fungicides before sowing to prevent soil-borne diseases.

Extra Practice Questions

  1. What is the scientific name for the common weed ‘Gokhroo’? (Ans: Xanthium)
  2. Name one stored grain pest that causes biotic damage. (Ans: Insects/Mites)
  3. How do aphids damage crop plants? (Ans: By sucking cell sap)
  4. Why should grains be dried before storage? (Ans: To reduce moisture content below 14% to prevent spoilage)
  5. Define hybridization in the context of disease resistance.