Meloidogyne incognita and M. javanica are the most damaging of root knot nematode species found in sugarbeet. Meloidogyne hapla is widely distributed, but not reported as a major problem on sugarbeet in California. Meloidogyne chitwoodi is found in Modoc and Siskiyou counties in northern California where its reproductive levels on sugarbeet are similar to those found on barley and less than those found on wheat, but no yield reductions have been reported. Infestations may occur without causing any aboveground symptoms. Seedlings infested by sugarbeet cyst nematode may have longer petioles than normal, with green or yellow leaves depending on the severity of infestation.
Plants are likely to be stunted and wilted.
Typically, storage roots will not be well developed, and will have excessive fibrous roots. Heavy infestation by root knot nematodes in sandy soils may cause plants to wilt and collapse. Symptoms of false root knot nematode infestation are similar to those produced by Meloidogyne spp. To make management decisions, it is critical to know the nematode species present and their population estimates. If a previous crop had problems caused by nematodes that are also pests of sugarbeet, population levels may be high enough to cause damage to an ensuing sugarbeet crop.