THE INFLUENCE OF CHITIN-UREA AMENDMENTS APPLIED TO AN ORGANIC SOIL ONA MELOIDOGYNE-HAPLA POPULATION AND ON THE GROWTH OF GREENHOUSE TOMATO

This experiment was conducted under greenhouse conditions to evaluate the efficiency of chitin-urea amendments to an organic soil against a Quebec population of the northern root-knot nematode (Meloidogyne hapl a) and to assess the pathogenicity of this population on tomato (Lycop ersicon esculentum). Chitin-urea amendments at 0.2 and 0.4% (vol:vol) were ineffective in reducing the preplant nematode populations. The fi nal M. hapla egg populations were significantly increased in chitin-ur ea amended soils, and a significant positive dosage effect was recorde d. Shoot growth of tomato plants was significantly reduced by M. hapla but was increased by chitin-urea. At harvest, fruit weights were neit her affected by M. hapla nor by chitin-urea amendments. The final M. h apla egg population was linked to lower N and P levels, and to higher Ca levels in leaf tissues.