How to Identify and Eliminate Root Knot Nematodes

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Nematodes or roundworms are the parasitic and almost microscopic worms found in almost every type of environment. As pathogens, nematodes can infect plants as well as animals. Nematodes that propagate on plants can be beneficial as well as detrimental. Depending on the species, either nematodes act as predators of cutworms (in gardens and fields, thus playing a beneficial role) or cause a commonly known condition in plants called root knots.

Nematodes that cause root knots in plants affect plant roots resulting in formation of galls or knots in them. As this particular type of nematodes feed on plant tissue, the toxins and bacteria released by them as waste cause this condition in plant roots. Garden plants such as carrots, corn, tomatoes, okra, peppers, lettuce, onions, rye, alfalfa, and chrysanthemums are particularly vulnerable to root knot nematodes due to their root structure. A typical root knot nematode plant will have root swelling, tangle, and deformities. The good part is root knot nematodes cannot stand cold temperatures; so if you reside in one of the colder regions where winters are long and summers short, you need not worry much about them. You also need not worry if your garden plants have dense root systems.  

Identifying Root Knot Nematodes 

  • At the initial stages of infection, the leaves of infected plants exhibit a yellowish tinge on them.
  • Try and uproot one of such infected plants. If the roots are swollen and has knots at the root tips or if the roots are deformed, the plant is definitely suffering from root knot nematodes.
  • For some reason, if the plant is drying out in spite of regular watering and no apparent disease on its body, possibly it is suffering from root knot nematodes. Due to knot formation in roots, water and nutrient-absorbing capabilities of the plant get severely affected.

Controlling Root Knot Nematodes

What makes root knot nematodes doubly fatal for plants is the fact that once these worms infect plants, they also help other bacteria and fungi to propagate at ground and upper ground level. Infection severity varies from plant to plant and depends on shape, size, and soil of plants. To control the infection, try the following methods.

  • In absence of any sure-shot cure, preventing root knot nematodes is the only way.
  • If you are buying seeds or seedlings or plants for your garden, make sure that they have been already treated with relevant nematode resistant materials. Buying any sort of garden plants from authorized seller will definitely help.
  • Before planting anything, clear the soil of any leftover roots and plant debris. Mulching will also be helpful in long run.
  • A regular crop rotation is necessary to keep these microscopic parasitic worms at bay. Plants with extensive root network will keep the population in check and in some cases, may even destroy the worms.
  • Another organic method is to use resistant cultivators and organic fertilizers on plants. Fertilizers made out of chicken dung, basil extract, garlic extract, neem seed extract, and pongam cake are found to be particularly helpful in fighting root knot nematode infections.
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