Biological control of weeds

Biological control has become today a key component of crop protection worldwide.

Biological approach to weed management involves various biological weed control agents such as pathogens, insects, nematodes etc.

In facts, insect and fungi have long been used in biological control of noxious weeds. The fact that weeds serve as alternative hosts to crop pathogens, insects and nematodes which, if properly used may eliminate certain noxious weeds.

Biological control of weeds was used initially only because other method had failed. The most important approach to biological control of weeds has been the classical, or importation method, which is the introduction of natural enemies from the area of origin of the target weed.

To be a good agent of biological control, an insect should have the ability to kill the target plant, or prevent its reproduction; it should have a high dispensability, a propensity for locating it host plant, adaptability to the host plant and to its environment and the capacity to reproduce at a rate sufficient to maintain control of its host.

Biological control of weeds requires many individual natural enemies to damage a weed, unless the natural enemy attacks the so-called ‘Achilles heel’ for that plant species.

Knowledge of microbiology, plant science and plant pathology is necessary for plant pathologists working to control plant pathogens or to control weeds with microbes.
Biological control of weeds