Root-knot nematodes are one of the three most economically damaging genera of plant-parasitic nematodes on horticultural and field crops. Root-knot nematodes are very small and they parasitic the roots of thousands of plant species, including monocotyledonous and dicotyledonous, herbaceous and woody plants.

They dwell in the soil, attack the roots of the plant to extract water and nutrients. As a result, large galls or “knots” can form throughout the root systems of infected plants. They will bring a lot of damage to plants.

Symptom of root knot nematodes

Under the ground

Root-knot nematode symptoms on plant roots are dramatic. However the most diagnostic root-knot nematode damage occurs under ground. By identifying these under ground symptoms, we can clearly know whether root-knot nematodes have already threat your crops.

The most distinctive symptom of root-knot nematodes infestation is the appearance of galls on primary and secondary roots, which become swollen and distorted with heavy infestations.

NOTICE：How to distinguish these symptoms is caused by root knot nematodes?

1. The appearance of the galls on the roots can be confused with nitrogen-fixing nodules commonly found in legumes. However it is easy to distinguish between them because the nitrogen nodules can be easily wipped off and the nematode galls cannot be removed.
2. In fact ,we can’t be sure that the symptom of the plants are caused by root knot nematode.we only remove the plant from the soil to examine its roots so that we can determine if it is caused by root knot nematode.

On the ground

Removing these special under ground features,root knot nematodes infestation also have other above ground symptoms. Root knot nematode damage results in poor growth, a decline in quality and yield of the crop and reduced resistance to other stresses. Seriously may lead to direct death.

1.Stunted, yellowed, or wilted, and can lead to premature death of the plant.

2.Sharp drop in output

How to control the root knot nematode?

Although these root knot nematodes may have problems, but they are not uncontrollable. Here are several common kinds of control methods.

Agricultural control

• Strengthen inspection and quarantine, and try to reduce or even eliminate the transmission of root-knot nematodes through seedlings, machinery, tools and other human factors
• Reasonable rotation can reduce the amount of soil nematodes and reduce the occurrence of diseases
• Treat sick strains thoroughly and fertilize and irrigate rationally
• Select anti-root knot nematode varieties or choose root-knot nematode rootstock for grafting

Biological control

The biological preparation has the advantages of good compatibility, eco-friendly. Bio nematicides is not easy to produce drug resistance, non-toxic and no side effects, and is harmless to humans and animals. They promote the development of plant roots and grow robust, so as to achieve the effects of disease prevention and treatment, increase of production and income. The most representative product is paecilomyces lilacinus.