Discovering you’ve got the presence of nematodes in your garden can be disheartening. In this article, we will help you identify the tell-tale signs of nematode infestation and give you some tips to still harvest a crop of tomatoes.
If your tomato plants are growing properly, and then the leaves start showing signs of curly unhealthy growth on branches, this may indicate a nematode problem. Cut off the affected branches and treat the plant for nematodes.
What are tomato nematodes?
Nematodes are microscopic eel-like worms that exist in almost every soil together with different bacteria and fungi. They attack the hair-like roots of the tomato plant causing swelling and knotting, leading to stunted growth, wilting, and reduced yields.
How do you know if you have tomato nematodes?
The only signs that you might have nematodes and your tomato plant is not doing well are the visible signs of yellowing and curling leaves and stunted growth of the plant. You can also gently dig into the root zone to see if you can see the roots forming knots or balls sometimes reaching the size of a marble.
What soils are susceptible to nematodes?
Nematodes can thrive in a variety of soil types, but certain conditions make soils more susceptible to nematode infestations. The factors that can contribute to soil susceptibility to nematodes include:
- Sandy Soil: Sandy soils with poor water-holding capacity are more susceptible to nematode infestations. Nematodes can move more easily through sandy soils, and the lack of moisture retention may make it challenging for natural predators to thrive.
- Low Organic Matter: Soils with low organic matter content are more susceptible to nematode problems. Organic matter supports beneficial microorganisms that can compete with nematodes for resources. Adding compost or well-rotted manure can help improve soil health and reduce nematode populations.
- Continuous Monoculture: Planting the same crop species in the same location season after season (monoculture) can lead to a build-up of nematodes that specifically target that plant. Crop rotation can help break the nematode life cycle and reduce infestations.
It’s important to note that nematodes are present in most soils, and not all nematodes are harmful to plants. In fact, many nematodes play beneficial roles in soil ecosystems.
How to prevent nematodes?
Here are some natural and organic methods to deal with tomato nematodes:
- Crop Rotation: Rotate your tomatoes each season to different areas of your garden. This will help disrupt the nematode life cycle.
- Marigold Plants: Planting marigolds (Tagetes species) in and around your tomato garden can help reduce nematode populations. Marigolds release compounds toxic to nematodes.
- Cover Crops: Plant cover crops like mustard greens during the off-season. These plants release natural compounds into the soil that can suppress nematode populations. Some cover crops, like mustard, can be chopped and incorporated into the soil before planting tomatoes. This process, known as biofumigation, releases compounds that are toxic to nematodes.
- Companion Planting: Some plants have natural nematode-repelling properties. Consider planting garlic, chives, or onions near your tomatoes, as these plants can deter nematodes.
- Organic Amendments: Add organic matter, such as well-aged compost or manure, to your soil. This not only improves soil structure but also promotes beneficial microorganisms that can compete with nematodes. See Growing Juicy Tomatoes: How to Prepare Your Soil for more
- Mulching: Mulch with organic materials like straw or wood chips. Mulch helps maintain soil moisture and temperature, creating a more favourable environment for beneficial soil organisms that can compete with nematodes. See Tips for Mulching Tomato Plants for more
Remember that these methods may not provide instant results, and a combination of strategies is often more effective. Regular monitoring of your garden and adjusting your practices accordingly is essential for successful nematode management.
What do if your tomato plant has nematodes?
Sometimes you don’t realise you’ve got a nematode problem until well into the growing season. If you are close to a tomato harvest and you need time for the plant to survive until your harvest, generously top-dress the tomato plant with compost, and mulch and keep moist. Molasses can control detrimental nematodes. Water occasionally with a solution of 1 cup of molasses dissolved in 9 litres of water.
Note: This treatment may also kill earthworms so limit soil applications of molasses.
By recognizing early signs and implementing organic solutions like companion planting, biofumigation, and crop rotation, you can cultivate healthy tomatoes without compromising your garden’s ecosystem.
CULTIVATE, LEARN & ENJOY!