Some effects of the nematodes Ditylenchus myceliophagus and Aphelenchoides composticola on the yield of the cultivated mushroom

The addition of one, ten and fifty Aphelenchoides composticola per ioo g compost at spawning reduced the total yield of sporophores by 26%, 30% and 42% respectively (P= 0·01), demonstrating a significant regression (P= 0·05) of yield on inoculum concentration. In pots inoculated at spawning with ten and fifty A. composticola per 100 g compost, cropping ceased after 12 weeks. The addition of twenty, 100 and 300 Ditylenchus myceliophagus at casing reduced the total yield of sporophores by 50%, 68% and 75 % respectively (P= 0·01). Cropping did not occur in pots inoculated at spawning, but continued for 9 weeks in pots inoculated at casing. The yield from pots inoculated at casing with either nematode was significantly greater (P= 0·05) than that from pots inoculated at spawning. When inoculated at spawning, peak populations of D. myceliophagus and A. composticola were reached 7 and 13 weeks, respectively, after spawning. Then the numbers present were unrelated to the number in the inocula.