Spathiphyllum plants within a greenhouse showed symptoms of wilting and yellowing of the oldest leaves. These are classic symptoms of a root disease.
Roots of young plants also showed dark discoloration mostly at the root tips. Serology tests for Phytophthora were negative and microscopic examination of the roots did not reveal spores nor hyphae of the usual root pathogen suspects. When looking at roots of older, wilting plants, the roots were soft, discolored, and covered in white fungal growth of hyphae and spores of the fungus, Calonectria spathiphylli.
It is usually assumed that the cause of wilting and dead plants is one of the more common root and crown rot pathogens such as Phytophthora, Pythium, Rhizoctonia, or Fusarium. However, it is best to have the cause of the problem accurately identified because chemical and cultural controls may be different. Misidentification wastes money and time.