Dealing with Root Knot Nemotode

Root Knot Nemotodes are plant-parasitic nematodes from the genus Meloidogyne. They exist in soil in areas with hot climates or short winters.

The following are observed foliar symptoms of Root Knot Nemotode:

  • Premature wilting in spots within the field
  • Leaf yellowing
  • Fruiting and flowering in vegetative stages.
  • Plant stunting
  • Plant death at mid to late stage

I have a very bad problem with Root Knot Nemotode attacking my chili pepper plants and culantro this year.

Once Root Knot Nemotode has been identified, here are the procedures to handle it.

  1. First, remove the infected plants and residues and discard it in the trash. Do not add the infected plants into the compost pile.
  2. Sanitize all gardening tools after each use to prevent soil contamination.
  3. Choose one of the three options to treat the infected soil:
  • Soil solarization
  • Bake the infected soil in the oven to kill the nemotode including all other living things inside the soil
  • Plant vegetations that are resistant to Root Knot Nematode in the infected area

Solarization – Soil solarization is a non-chemical environmentally friendly method for controlling pests using solar power to increase the soil temperature to levels at which many soil-borne plant pathogens will be killed or greatly weakened. Here is the procedure for soil solarization:

  1. Clear the area of plants and debris.
  2. Water the soil deeply until it is wet.
  3. Cover the area with clear 4 mil plastic tarp or painter’s tape. White or black plastic is not recommended since it doesn’t allow enough heat to be trapped.
  4. Bury the plastic edges in the soil to trap the heat.
  5. Leave the plastic in place for at least 4 weeks in the hottest part of the summer.
  6. Remove the plastic.

Baking the soil – Carefully remove the infected soil area and place it in a deep aluminum baking tray. Bake the infected soil for 30 minutes at 120 degrees. This will kill all the root knot nemotode and also all the living things inside the infected soil. Remember to sanitize the gardening tools used including the gardening gloves. (I will need to test this option out to see if it will make my kitchen stink from the soil.)

Intercropping RNM resistance plants- Intercropping is a multiple cropping practice that involves growing two or more crops in proximity. The following is a list of plants that are resistant to Root Knot Nemotode. I will add more plants list that are resistant and that I would actually want to grow and eat in the garden.

  • French Marigolds – I learned there are several varieties of marigolds and it’s the French marigolds that are used in the garden to repel pest and prevent root knot nemotode. When the plants mature and start to die, chop it or pulled it out and bury it into the soil area.
  • cabbage
  • mustard
  • kale
  • bok choy
  • radish

Result: I’ll update with which method worked most effectively in my garden where the infected soil are located.

Resources & For more information, visit the following articles:

  1. https://agrilifeextension.tamu.edu/library/gardening/soil-solarization/
  2. https://www.plantwise.org/KnowledgeBank/pmdg/20177800177
  3. https://content.ces.ncsu.edu/control-of-root-knot-nematodes-in-the-home-vegetable-garden

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