Biological weed control is a method of controlling weeds using natural enemies, such as insects, fungi, bacteria, or other organisms, rather than synthetic herbicides or other chemicals. This method is often used in agricultural settings to manage weeds in crops or pastures.

In other words BIOLOGICAL WEED CONTROL This involves use of living organisms to control weeds.

The use of natural enemies to control weeds can be effective and environmentally friendly. Natural enemies can help reduce weed populations without causing harm to other plants or the environment. Additionally, this method can be cost-effective, as it requires less labor and equipment than other weed control methods.

Examples of Biological weed control agents

i) Use of goats to feed on leaves and flowers of weed pastures e.g. Couch grass, star grass, elephant grasses

ii) Use of weevils e.g. – Neochetina eichhornae controls water hyacinths.

NB: The enemy of a weed either skills the weed or suppresses its growth


Advantages of biological weed control

  • The method is easy to carry out
  • The method is cheap as far as the farmers situation is concerned. Once established, biological control agents can continue to control weeds for years, reducing the need for costly herbicides or other chemical treatments.
  • Environmentally friendly: Biological weed control is a sustainable and environmentally friendly method of weed management that does not harm the soil, water, or air.
  • Targeted approach: Biological weed control is a highly targeted approach that targets specific weed species, leaving other plants unaffected
  • Reduced resistance: Over time, weeds can become resistant to chemical herbicides, making them less effective. Biological control agents, on the other hand, work in a different way, so there is less risk of resistance.
  • Lower risk of accidental exposure: Biological weed control agents are typically non-toxic to humans and animals, reducing the risk of accidental exposure and minimizing the need for protective clothing and equipment.

Disadvantages of Biological weed control

  • To find the best /right biological weed control agent, is a long and slow process which ends up being an expensive venture.
  • Biological weed control agents may attack crops after eradicating weeds
  • The agent may not be in large Number to control weeds effectively or it might take long to bring weeds under control.
  • The Biological agents may not effectively eradicate weeds but maintain a certain population of weeds on which they can survive.
  • Once the agent has been released to the garden it might be very difficult to tell whether the agent is working or Not

  • It requires a lot of research to come up with suitable biological weed control agent. Developing effective biological control agents requires significant research and development, and there may not be suitable agents available for all weed species.
  • Regulatory challenges: The use of biological control agents may be subject to regulatory oversight, which can create challenges for their adoption and deployment.


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