Root-knot nematode of wheat
Root-knot nematodes are one of the most destructive plant-parasitic nematodes. Approximately ten species of Meloidogyne are known to infect wheat. The root-knot nematode commonly produces small, curved or horseshoe shaped-galls near root tips. Typically, galls are larger and easier to recognize toward the end of the growing season. Severely infected plants are often stunted with few tillers and older leaves are yellowish.
Root-knot nematodes primarily overwinter as eggs. Nematodes typically infect wheat in early spring and females establish permanent feeding sites within the root. Males remain mobile. Swollen females can be found inside galls and release eggs on the root surface by the middle of summer.
Effective resistance to root-knot nematode in wheat has yet to be identified. Management of this nematode is primarily through crop rotation with a poor host crop. Oat is considered a relatively poor host compared to other cereal crops. Given that the host range of Meloidogyne species differs, species identification is needed to select the best rotational crop. Nematicide applications are not economically feasible.