The website has the complete lesson note for all the subjects in secondary school but this piece showcases the Lesson Note On The Effects of Weeds Control Methods on Vegetation and Soil. You can use the website search button to filter out the subject of interest to you.
CLICK HERE to download the complete Document: DOWNLOAD HERE
Adverse effects of weeds/Problems posed by weeds in Agriculture/ Economic Importance of weeds
The harm done by weeds is due mainly to their competition with crops. these are some of the reasons why weeds pose a challenge to farmers, hence a need for them to be controlled. The effects or economic importance of weeds include:
- Weeds compete with crops for space.
- Weeds compete. With crops for sunlight.
- Weeds compete with crops for nutrients.
- Weeds harbour crop pests and diseases.
- Weeds compete with crops for soil moisture.
- Weeds result in loss of crop yield.
- Weeds compete with crops for oxygen.
- Weeds reduce the palatability of some pasture grasses.
- Weeds reduce the quality of crops.
- Weeds increase farmers’ cost of production.
- Some weeds are toxic to farm animals.
EVALUATION:
State five effects of weeds on crops.
Sub-Topic 2: Dispersal of Weeds (weed dissemination)
Weeds are widely dispersed through various adaptations. This is one of the reasons why weeds survive and are found in almost all cultivated fields.
Meaning: This is the process by which seeds of weeds, fruits and propagules are carried from one place to another through one agent or the other.
Agents of weed dispersal are
- Man and animals
- Water
- Wind
- Explosive mechanism
- Farm tools, machines and implement.
Dispersal by man and animals:
