Abstract
The strains of fungus which belong to Coniothyrium genus were isolated from leaf spoot of Yucca. The isolated strain can grow easily and forms characteristic colonies on Saido's soy agar. There are definite differences, according to other authors, (By Miyake et Hara 1911) Pycnidio-spore are usually formed ellipsoidal, dark brown, 4$\times$2. 5-4. $O\mu$ in size, whereas isolated strains are globose, yellowish brown, 2.8-4.2$\mu$ in diameter. The positive inoculation test can be attained by burned petridish method, preserving it in incubator at 28$^{\circ}C$, and the pycnidio-spore can be reisolated from the inoculated portion. (Photo.7) Up to the present day there is no report for leaf spot of Yucca caused by Coniothyrium sp.. Comparing the writer's isolate with those fungi described(leaf spot of alloe, rose canker and elm canker etc.) hitherto, there are no accordance in the symptom and especially in morphological charactgers and Pathogenicitys.