Four fungi, Paecilomyces variotii, Mucor hiemalis, Aspergillus petrakii, and Penicillium simplicissimum were isolated frequently from secondary-treated sewage water used for irrigation. The effect of these fungi on population development of the citrus nematode (Tylenchulus semipenetrans) on lime (Citrus aurantifolia) seedlings was tested. Nematode populations recovered from roots and soil were greater when seedlings also were inoculated with P. variotii and M. hiemalis than when seedlings also were inoculated either with A. petrakii and P simplicissimum or when no fungus was added.
