How to Treat Root Knot Nematodes

Root knot nematodes can quietly wreak havoc beneath the soil surface, leading to stunted growth, poor yields, and stressed crops. For commercial growers committed to sustainable, soil-friendly practices, identifying and treating this pest without compromising long-term soil health is critical. If you are noticing signs of root knot nematodes damaging your crop, let’s explore some ways to eliminate them and prevent them in the future. 

What are Nematodes?

Nematodes are microscopic, worm-like organisms that live in the soil. While some nematodes are beneficial, others are parasitic and can damage plant roots.

Root knot nematodes fall into the harmful category. These pests invade the roots of crops, disrupting water and nutrient uptake. As their name suggests, they cause the formation of “knots” or galls on roots, leading to weakened plants and diminished productivity.

Root knot nematodes affect a wide variety of crops, including vegetables, fruit trees, and row crops. This is frustrating if you have a garden, but detrimental if you are growing hundreds of acres of crops on a commercial farm. 

Luckily, there are ways to prevent and treat root knot nematodes. First though, we need to identify them!

How to Tell if Your Crop is Infected by Root Knot Nematodes

Carrots infected by root knot nematodes

Ideally, we are monitoring the soil and preventing this pest problem before it begins, but we know that isn’t always possible, and sometimes these nematodes infect the soil quickly and stealthily. 

Detecting a root knot nematode problem early is key to minimizing crop losses. While the symptoms above ground may look similar to nutrient deficiencies or drought stress, a closer look at the root system often tells the real story.

Signs of Root Knot Nematodes

• Stunted or uneven plant growth
• Yellowing or wilting despite adequate water and nutrients
• Poor yields
• Swollen, knotted root structures (visible upon inspection)

If you suspect nematode damage, uproot a few plants and examine the roots. Root galling (lumpy swollen roots) is a telltale sign of root knot nematode infestation.

Some types of soil tests can confirm the presence and density of nematodes. If you have noticed these signs in your roots, you should conduct a soil test to formulate the proper treatment plan.

Treatments Options for Root Knot Nematodes

Conventional, chemical nematicides can be effective but often come with environmental drawbacks. Chemical nematicides like 1,3-dichloropropene and sodium methyldithiocarbamate will likely kill your nematodes, but will harm your soil’s healthy organisms also. If you are looking for a treatment option that maintains soil health and eradicates your root knot nematode issue we are here to help! 

All-Natural Treatments for Root Knot Nematodes

The best way to treat root knot nematodes is to cultivate healthy soil. In order to do this, you can’t kill all your organisms and bacteria in the soil, you have to balance them. Let’s look at some ways to do that so you can continue to produce hearty, healthy yields for seasons to come. 

Cover Cropping

Cover cropping is one of the most powerful regenerative tools for managing pests and building healthier soil. Certain cover crops have natural biofumigant properties or disrupt nematode life cycles, reducing their population over time.

Using a Mustard Cover Crop 

Mustard cover crops, in particular, are highly effective for preventing root knot nematodes. Brassica species (like mustard) contain compounds called glucosinolates. When incorporated into the soil, these compounds break down into isothiocyanates, which are natural chemicals with fumigant-like effects that suppress soil-borne pests, including root knot nematodes.

To use mustard as a biofumigant:

• Plant mustard cover crops in the off-season or during fallow periods.
• Mustard needs to be blooming for about 5-7 days for the best fumigation effect.
• Mow and incorporate the green plant material into the soil while it’s still lush and actively growing.
• Allow time (2–3 weeks) for the biofumigant effect to occur before planting your next cash crop.

Keystone Bio-Ag also offers a cover crop blend called ReCoverIt FUMIGANT. This blend of brown mustard, buckwheat, spring oats, spring peas, nematode control radish, and African cabbage is designed specifically to naturally fumigate the soil and prevent root knot nematodes.

Improve Soil Diversity and Microbial Activity

Healthy soils are naturally more resilient against pests like root knot nematodes. Building organic matter and microbial diversity helps create a soil environment where beneficial organisms can outcompete or suppress harmful ones.

We recommend a few different microbial inoculants to help revive your soil and induce a sustainable population of healthy organisms within it. 

Algae

Algae are becoming a more popular resource and tool in agriculture due to their unique ability to support microbial life and improve soil function. When applied to the soil, certain algae can stimulate microbial activity, increase carbon cycling, and enhance nutrient availability.

EnSoil Algae is a specific strain of algae produced in a high-quality environment. It has been heavily researched and is endorsed by Dr. James White of Rutgers University because of its beneficial impact on the rhizophagy cycle.

Ensoil Algae will help make conditions less favorable for root knot nematodes while improving root zone oxygenation and increasing nutrient uptake efficiency. 

BioQuest

Paired well with Algae, BioQuest Foundation provides your soil with 20+ beneficial microbes that will provide an organic treatment to not just root knot nematodes, but to many issues that will arise from unhealthy soil. If your soil lacks nutrients provided by life in the soil, you will then need to invest more in products to fertilize and maintain your crops in the long run. 

Consult a Soil Health Expert

Every farm and plot of land is unique, and so is its soil. If you’re battling root knot nematodes or looking to prevent future infestations then the best first step is to consult a soil health expert.

At Keystone Bio-Ag, we offer personalized regenerative agriculture consulting for commercial growers. Our team can help you:

• Diagnose nematode pressure through soil testing
• Develop a custom cover cropping plan
• Select and apply biological treatments like BioQuest and Ensoil Algae
• Transition away from chemical inputs while maintaining yields

Don’t let root knot nematodes compromise your growing season. Reach out today for a consultation and start building a more resilient, productive farm from the soil up.