Epidemiological Studies of Rice Blast Disease Caused by Pyricularia oryzae Cavara. VI. Measurement of Sporulation on Blast Lesions of Naturally Infected Leaf.

Sporulation capacity of the blast lesion was studied in the field condition during July, 1991 at Icheon, Korea.Sporulation counting was continuously able for 9 days on undetached leaves.Among these leaves, 14.8mm size lesion recorded the highest count, 12,540 spores.More than 5•~104 spores were formed on many detached lesions.The amount of spores formed on the upper surface was several times to more than tenfold of lower surface of the same lesion, and only 1 to 12% spores out of total sporulation amount was released.