Suppression of Meloidogyne incognita by combination of olive pomace or wheat straw with urea

The suppressive action of soil amendment with exhausted olive pomace and wheat straw, alone or in combination, and their possible synergysm with urea were tested on Meloidogyne incognita on tomato in three glasshouse experiments. Olive pomace reduced the nematode reproduction at all the rates tested, but it was phytotoxic at high dosages. Its nematicidal effect was improved by the addition of urea at rates > 500 mg N/Kg soil. Wheat straw suppressed the population of M. incognita at all the dasages tested. Combining with urea improved nematicidal effect of the straw and limited the phytotoxic effect of the highest rates of the fertilizer. Mixing olive pomace with straw improved the nematicidal effect of olive pomace but did not prevent phytotoxicity at the highest rate tested.