NEMATODE DISEASES OF SOME FLOWERING ORNAMENTAL PKANTS

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Enormous interest has been shown by plant pathologists in nematodes causing plant diseases. These nematodes cause the diseased conditions cither alone or in conjugation with fungi or bacteria. Although much of the work deals with nematode diseases of ficld crops, there is a relativcly large amount of literature on nematode diseases of flowcring ornamental plants especially those grown in grcenhouses. A nematode disease of Chrysan-themum was reported as early as 1890 in England and 1901 in the United States. There is evidence that considerable losses to flowering ornamental plants like Irises, Narcissus, ctc. (5) are caused by nematodes, although exact loss in numeral figures is lacking. The typical losses on flowering ornamental plants are poor growth and reduction either in number or size of flowers. Importance of nematode diseases on ornamental plants can be easily noticed by the fact that a U.S. Federal quarantine was passed as early as 1926 to restrict the move-ment or Narcissus bulbs from infested areas.