THE RED PLAGUE OF " SUGI " (Cryptomeria Japonica) 



SEEDLINGS 



By SEIICHI KAWAMURA, Botanist of Forest Experiment Station 



Since the " Akagarebyo " or red plague, which attacks " Sugi " (Cryp- 

 tomeria japonica) seedlings, became known a few years ago, the plague 

 is .reported to have spread to various parts of Japan. The one or two 

 years old seedlings suffer most while larger ■ saplings are less liable to 

 attack, and even when strong sound saplings are infected by the plague, 

 they can resist the attack. 



The writer has made personal investigations since December, 1911, 

 in various places where the plague has spread. The conclusion reached is 

 that the plague attacks only seedlings of " Sugi " (Cryptomeria japonica) 

 under five years of age, and that the plague is met with neither in other 

 coniferous trees nor in broad-leaved trees. The plague cannot be assumed 

 to have been caused by physiological derangement in seedlings, owing to 

 the influence of climate, unfavorable condition of soil or else by human 

 agency. The " Yoshino Sugi " has ever been seriously infested by Pestalozzia 

 Shiraina, and even though he often came across with this fungus on the 

 dead leaves of " Sugi " seedlings infected by this plague he assigns the 

 plague caused to other origin than this fungus. Thus, he has every 

 reason to name the plague with a specific designation. 



The plague is now reported throughout the country from Kagoshima in 

 the South up to Aomori in the North and fear of further diffusion alarms 

 the foresters of the country. The authorities and the people are now 

 striving to fight with this formidable pestilence. 



Three different fungi are found on " Sugi " seedlings infected with the 

 plague, viz., Phyllosticta, Cercospora and Pestalozzia. Of these, Pestalozzia 

 is far rarer than the other two fungi and is generally found in association with 

 other parasitic fungi mostly on old decayed leaves, so that it (Pestalozzia) 

 could not be taken as the specific cause of the plague. We must assign the 

 origin of this trouble therefore either to Phyllosticta or else to Cercospora. 



In the present treatise, we shall discuss only the nature of Phyllosticta, 

 since investigations are still unfinished so far as Cercospora is concerned. 



