Pathogenicity of Pythium aphanidermatum to Chrysanthemum in Combined Inoculations with Belonolaimus longicaudatus or Meloidogyne incognita.

Rooted cuttings of 'Iceberg' chrysanthemum in steamed soil were inoculated with the nematodes Belonolaimus longicaudatus, and Meloidogyne incognita, alone and combined with Pythium aphanidermatum, a fungus pathogen of chrysanthemum. B. longicaudatus alone severely restricted the root system; with P. aphanidermatum also present, plant weight and height were further reduced and onset of symptoms was earlier. M. incognita + fungus interaction was similar but less intense. The fungus suppressed egg production of M. incognita but not the reproduction of B. Iongicaudatus. However, all three pathogens combined significantly suppressed reproduction of both nematodes and caused greatest inhibition of plant growth.