Horticulture :: Vegetables:: Tomato

Tomato (Solanum lycopersicum )


Root-knot nematode, Meloidogyne incognita

       Root knot nematode, Meloidogyne incognita is a obligate, sedentary endoparasites. M. incognita is one of the major constraints in the production of tomato in tropical and subtropical regions. It causes 11 – 35% yield loss in tomato. Root knot remains a serious issue in both nursery and field conditions.

Mode of spread

      Seedlings or planting materials, irrigation water and farm implements.


Above ground symptoms

  • Infested seedlings may not survive after transplanting.
  • Stunted growth of the plants.
  • Disease appearance in patches under field conditions.
  • Leaves show chlorosis and yellowing.
  • Growth may be retarded.
  • Plants show “Day wilting” symptom.

Below ground symptoms

  • Primary galls are small and induced by swelling which coalesce to form larger secondary gall s/ knots on the root.
  • Root system is reduced to a severely galled and a completely disorganized vascular system.
  • Sometimes the galled tissues are invaded by secondary pathogens and results in root wilting.
              Root knot galls on tomato


  • Raised of seedlings in nematode free soil and use of nematode free planting materials.
  • Nursery application of Glomus fasciculatum@ 100g/m2.
  • Soil solarization in nursery beds with white or transparent sheet LLDPE 25 gauge thickness during summer.
  • Removal and destruction of nematode affected roots of previous crop.
  • Summer ploughing of field.
  • Crop rotation with non-host crops like mustard, sesame, maize, wheat and millets.
  • Intercroping with marigold @ 4:1 ratio.
  • Soil application of talc based formulation of Purpureocillium lilacinum @ 2.5 kg/ ha along with 250kg of FYM.
  • Soil application of carbofuran 3G @ 1 kg a.i./ha (33 kg/ha).
                                                                  Stunted and yellowing of tomato plant
Updated on Jan, 2023
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