Biological Control of Plant-parasitic Nematodes

Biological control of nematodes may be defined as the action of natural antagonists maintaining nematode population densities at lower levels than would otherwise occur. Development of harmful densities of plant-parasitic nematodes in soil is regulated by numerous factors, including host suitability and natural antagonists. Because of the complexity of the soil environments, there are limitations to capitalize on these antagonists. Biological control of nematodes is often visualised as the mass introduction of a biological control agent that results in an immediate reduction of nematode population densities and an immediate response with increased crop yields and an economic return on investment. In other words, this involves inundating nematode-infested soil with one or more antagonists that act as a biopesticide. Another approach is to enhance the activity of indigenous antagonists by manipulating the environment through cultural practices. Both strategies face challenges and are unlikely to be practical in agricultural production systems unless used as part of an integrated management programme.