Lesson Notes By Weeks and Term v4 - SHS 3

Lesson Video

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Performance objectives

• Discuss the common methods of weed control.
• Analyze the advantages and disadvantages of each method.
• Understand safety protocols for weed control.
• Evaluate the impact of weeds on crop health and yield.

Lesson summary

This lesson focuses on the various methods used to control weeds on our farms. Weeds are a major challenge for every Ghanaian farmer, from the maize farmer in the Afram Plains to the vegetable grower in Akwapim. They compete with our crops for sunlight, water, and nutrients, drastically reducing yields. However, the methods we use to fight these weeds can also pose significant health risks to farmers, our communities, and consumers if not done correctly. This lesson will equip you with the knowledge to control weeds effectively while prioritising your health and the safety of our environment.

Lesson notes

2.1 What is a Weed?

A weed is simply a plant growing where it is not wanted. It is a plant "out of place". For example, a maize plant growing in a cassava farm is a weed in that context. Weeds are generally characterized by their ability to grow aggressively, produce many seeds, and survive in difficult conditions.

Common Weeds in Ghana: Spear grass (*Imperata cylindrica*) Goat weed / "Acheampong weed" (*Chromolaena odorata*) Wire weed (*Sida acuta*) Water leaf (*Talinum triangulare*) Pigweed (*Amaranthus spp.*)

Why are Weeds a Problem? (Negative Effects) Competition: Weeds compete with crops for sunlight, water, soil nutrients, and space, leading to stunted growth and reduced yields. Harbouring Pests and Diseases: Weeds can serve as alternative hosts for crop pests (like insects and rodents) and diseases (like fungi and viruses). Allelopathy: Some weeds release chemical substances into the soil that can inhibit the growth of nearby crop plants. Reduced Quality of Produce: Weed seeds can mix with harvested grains (like maize or rice), lowering their market value. Increased Cost of Production: Farmers spend significant time, energy, and money controlling weeds. 2.2 Methods of Weed Control

Evaluation guide

• Discuss the methods of weed control in Agricultural production.
• Inquiry -based learning: Learners in mixed -ability/mixed -gender groups surf th e
• internet for information on weed control.
• Managing talk for learning: Learners in mixed -ability groups discuss the methods of