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

The following plants in my garden are infested with Root Knot Nemotode in 2021:

• tomatoes
• cucumbers
• culantro
• chili pepper plants
• Da Vincas or periwinkle
• oak tree
• Chinese golden celery

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
• Beneficial nematode application
• Intercropping
• Monterey’s Nemotode Control (chemical)

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.

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 said resistant to Root Knot Nematode. I’ll just have to test it out to believe it.

• 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 nematode. When the plants mature and start to die, chop it or pulled it out and bury it into the soil area. (Tested, French marigolds may not host the RNK, but had the potential to attract other bad nematodes and that’s what happened in my experience growing them in the front yard. – insert image here)
• cabbage – to be tested
• mustard – true
• kale – true
• bok choy – true
• radish – tru

Result: I updated with which method worked most effectively in my garden where the infected soil are located. I spent at least $60 buying 3 beneficial nematodes and a hundred dollar worth of crushed lobster and crab shells to till into the infected soil areas. I noticed the bad nematodes area has downsize but I have not completed rid the problem. Factor to know: Applying beneficial nematodes require keeping the soil consistently moist for the first two weeks. Well, it’s the hottest summer time in zone 9B, that was a mistake to apply beneficial nematode at this time of the year. I would recommend to apply beneficial nematode during rainy season or cooler season rather than the hot summer time. I think it would have been more effective. I till in a cup of crushed crustacean shell in the raised beds and infected soil. Hopefully it’s working.

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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