Knots and swellings on my okra and brinjal roots with stunted yellow plants

The bead like knots and swellings on the roots, with stunted yellow plants that wilt in the afternoon and the same bad patches every year, are caused by root knot nematodes. These tiny soil worms invade the roots, form galls and block water and nutrient uptake, which is why watering does not fix the wilting. Management is mainly cultural and preventive since chemicals are limited and hazardous. In summer, deep plough and solarise the soil by covering moist beds with clear plastic for several weeks to heat kill nematodes. Rotate with non host crops like cereals or marigold, in fact growing marigold as a trap crop reduces populations well. Add lots of organic matter and apply biocontrol agents such as Paecilomyces or Trichoderma, and use nematode tolerant varieties where available. Avoid moving infested soil to clean fields on tools. Get a soil and root sample checked at your KVK to confirm and to plan the rotation.