Root Knot Nematode
Microscopic roundworms that invade root tissue and cause the plant to form swollen galls, disrupting water and nutrient uptake throughout the whole plant.
Symptoms to Look For
- Irregular swellings or galls on roots ranging from pea-sized to large knotted masses
- Persistent wilting during hot weather despite moist soil
- Yellowing, stunting, and poor cropping with no obvious above-ground cause
Affected Plants
Organic Solutions
Resistant varieties
Choose tomato and pepper varieties with N (nematode) resistance ratings in the seed catalogue - these prevent reproduction and protect yield.
Marigold cover crop
Grow Tagetes patula (French marigold) as a dense cover crop for a full season before planting susceptible crops - root exudates suppress nematode populations significantly.
Soil solarisation
Cover moist, cultivated soil with clear plastic for 6 - 8 weeks during the hottest summer months to heat the top 30 cm to nematode-lethal temperatures.
Prevention
- Practice strict crop rotation, keeping records of where susceptible crops grew in previous years
- Avoid moving soil from infested beds on tools or boots
- Incorporate plenty of well-made compost to encourage beneficial soil organisms that compete with nematodes
Garden, by Willowbottom recommends only organic, wildlife-friendly solutions. No synthetic pesticides, no harmful chemicals - ever.