Plant-parasitic nematodes attack various crops which cause both qualitative and quantitative losses. Among the various method of pest control, the most important is the exclusion which is also known as quarantine measure.
The principle involved in enacting quarantine is exclusion of nematodes from entering into an area which is not infested, in order to avoid spread of the nematode. Quarantine principles are employed to restrict the movement of infected plant materials and contaminated soil into a state or country.