Edexcel iGCSE Biology-6.4 Crop Plants: Pest Control- Study Notes- New Syllabus

Pest Control in Crop Plants

🌱 Introduction

Pests are organisms (insects, fungi, bacteria, weeds, etc.) that damage crops, reducing yield and quality.
Pest control is necessary to:

• Protect crops from damage
• Maintain high yield and quality
• Reduce economic losses for farmers

⚡ Reasons for Pest Control

• Reduce Crop Loss → Pests can destroy leaves, roots, fruits, or seeds.
• Prevent Spread of Diseases → Many pests transmit plant pathogens.
• Maintain Food Quality → Damaged crops may be unsellable or unfit for consumption.
• Economic Benefit → Reduces financial loss for farmers.

🛡️ Methods of Pest Control

1. Pesticides (Chemical Control)
   Definition: Chemicals used to kill or repel pests.
   Advantages:
   • Fast-acting → quick pest reduction
   • Can control large-scale infestations
   • Easy to apply in many crops

   Disadvantages:

   • Harmful to humans and animals if overused
   • Kills beneficial insects (e.g., pollinators, predators)
   • Pests may develop resistance over time
   • Can cause soil and water pollution
2. Biological Control
   Definition: Using natural enemies of pests to control them.
   Examples:
   • Ladybirds eat aphids
   • Parasitic wasps lay eggs in caterpillars
   • Predatory nematodes attack soil pests

   Advantages:

   • Environmentally friendly → no chemical pollution
   • Sustainable → pests unlikely to develop resistance
   • Can target specific pests without harming other species

   Disadvantages:

   • Slower to act than chemicals
   • Effectiveness depends on survival of natural enemies
   • May require careful monitoring and management

📊 Comparison Table

💡 Quick Recap
Pest control → Protect crops, maintain yield & quality
Pesticides → Fast but risky
Biological control → Safe but slower
🧠 Mnemonic: “Chemicals Kill Fast, Nature Wins Last”