Effects of Heavy Metals and Meloidogyne hapla on Celery Grown on Organic Soil Near a Nickel Refinery. S. Bisessar, Plant Pathologist, Phytotoxicology Section, Ontario Ministry of the Environment, Toronto, Canada M5S 1Z8. R. J. Rinne, Plant Ecologist, Phytotoxicology Section, Ontario Ministry of the Environment, Toronto, Canada M5S 1Z8, and J. W. Potter, Nematologist, Agriculture Canada Research Station, Vineland Station, Ontario L0R 2E0. Plant Dis. 67:11-14. Accepted for publication 5 May 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-11.

A field plot experiment to study the interactive effects of heavy metals (primarily nickel) and the root-knot nematode (Meloidogyne hapla) on celery was conducted on a muck farm adjacent to a nickel refinery in southern Ontario. The treatments used were control soil (no metal or nematodes), nonmetal soil plus nematodes (inoculated), heavy metal soil (nickel at 7,500 ppm, copper at 800 ppm, and cobalt at 100 ppm) without nematodes, and heavy metal soil plus nematodes. The nematode treatment alone resulted in an average celery shoot weight 12% less than the controls (significant at P = 0.05), whereas heavy metals alone resulted in shoot weight 79% less than the controls. The combined effect of nematodes and heavy metals was a shoot weight 85% less than the controls. The roots of nematode-inoculated plants grown in heavy metal soil had significantly more nematode galls than did the roots of inoculated plants grown in nonmetal soil, indicating that heavy metals, primarily nickel, predisposed celery to greater attack by M. hapla.

Keyword(s): Apium graveolens, crop losses, metal pollution, soil contamination.