THE INFLUENCE OF PASTURE SPECIES AND TIME OF DEPOSITION OF SHEEP DUNGON INFESTATION BY NEMATOPHAGOUS FUNGI

Invasion of sheep dung by fungi which parasitise nematodes (nematophag ous fungi) was investigated in a field trial in New Zealand. In Januar y, March and May, sheep dung was placed bn plots of the following past ure species: Agrostis capillaris, Bromus willdenowii, Cichorium intybu s, Dactylis glomerata, Festuca arundinacea, Holcus lanatus, Lolium per enne, Medicago sativa, Trifolium repens, and a mixture of L. perenne a nd T. repens. Subsamples of dung were retrieved at fortnightly interva ls for up to 12 weeks and examined for the presence of nematophagous f ungi. Nematophagous fungi were isolated from 52% of 730 dung samples r ecovered during the trial, with 47% of samples infested at 2 weeks aft er deposition. The most commonly isolated fungi (and their frequency o f occurrence) were Harposporium leptospira (23%), Anthrobotrys oligosp ora (10%), Monacrosporium candidum (8%) and H. anguillulae (6%). Pastu re species had no significant effect on the percentage of dung samples infested by nematophagous fungi at 2 weeks after deposition. Mean dun g infestation was significantly higher at 2 weeks after deposition in May than in January, while mean dung infestation in March was intermed iate between, and significantly different from that in May and January . Dung had disappeared from all plots by 8 weeks after deposition in M ay, but remained on most plots at 12 weeks after deposition in January and March. (C) 1997 Elsevier Science B.V.