Abstract
SUMMARY The relation of temperature to germination of conidia and appressorium formation in Colletotrichum lagenarium is discussed. The optimum temperature for germination of conidia is from 20 to 32 C, and 20 to 26 C was the optimum for appressorium formation. Conidia that germinated at 32 C seemed to lose the ability to form appressoria. All conidia kept at 32 C for 2–12 hr germinated, but they did not form appressoria.