A nematicide is a type of chemical pesticide

Pesticide

Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...

 used to kill parasitic nematode

Nematode

The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

s.
One common nematicide is obtained from neem cake

Neem cake

Neem cake organic manure is the by-product obtained in the process of cold pressing of Neem tree fruits and kernels, and the solvent extraction process for neem oil cake....

, the residue obtained after cold-pressing the fruit and kernels of the neem

Neem

Azadirachta indica is a tree in the mahogany family Meliaceae. It is one of two species in the genus Azadirachta, and is native to India growing in tropical and semi-tropical regions. Its fruits and seeds are the source of neem oil...

 tree. Known by several names in the world, the tree was first cultivated in India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 in ancient times and is now widely distributed throughout the world. The root exudate of marigold (Tagetes

Tagetes

Tagetes is a genus of 56 species of annual and perennial mostly herbaceous plants in the sunflower family . The genus is native to North and South America, but some species have become naturalized around the world. One species, T...

) is also found to have nematicidal action. Nematophagous fungi, a type of carnivorous fungi, can be useful in controlling nematodes, Paecilomyces

Paecilomyces

Paecilomyces is a genus of nematophagous fungus which kills harmful nematodes by pathogenesis, causing disease in the nematodes. Therefore the fungus can be used as a bio-nematicide to control nematodes by applying it to soil.-Species:...

being one example.

Prior to 1985, the persistent halocarbon

Halocarbon

Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds...

 DBCP was a widely used nematicide and soil fumigant. However, it was banned from use after being linked to sterility

Infertility

Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...

 among male workers; the Dow Chemical company was subsequently found liable for more than $600 million in damages.

Besides chemicals, soil steaming

Soil steam sterilization

Soil steam sterilization is a farming technique that sterilizes soil with steam in open fields or greenhouses. Pests of plant cultures such as weeds, bacteria, fungi and viruses are killed through induced hot steam which causes their cell structure to physically degenerate. Biologically, the...

 can be used in order to kill nematodes. Superheated steam is induced into the soil which causes almost all organic material to deteriorate.