Phialospores of verticillium malthousei Ware were atomized onto acclimatized water agar and incubated for 3, 6, 9, 12, and 24 hr at 12 to 36 degrees C intervals. Germination occurred at all temperatures exclusive of 36 degrees C with maximum germination (90-98%) occurring in 24 hr at 12 degrees C, 12 degrees C, 12 HR at 18 degrees C, 9 hr at 24 degrees and 30 degrees C. Volatiles from: 1) horse manure compost colonized by Agaricus bisporus; 2) mycellium impregnated casing (soil); or 3) casing supporting mature and immature mushrooms had no statistically significant effect on spore germination of V. malthousei when measured after 12 hr at 24 degrees C. However, a tendency towards inhibition after 6 and 12 hr at 24 degrees and 12 degrees C, respectively, suggests the inhibition is temperature and time dependent. This dependency was noted with two substrates, colonized compost and casing which supported sporocarps.