Notes on Some Diseases of Rice and 



Camphor Tree. 



By 



Gompei Kurosawa. 



I. On the "Naiyake" of Rice-Plant. 



In the early part of June, 1900, young rice plants in the vicinity of 

 Mitsukemachi, Totomi, were severely attacked by a disease called " Naiyake " or 

 young rice plant rot. The result of my study of the disease was published in the 

 Bulletin No. 39 of the Shizuoka-Prefectural Agricultural Society, Sept. 1900. As 

 the direct cause cf the disease I discovered a new species of Helminthosporium 

 to which I gave the name Helminthosporium Oryzae. The disease was also 

 studied by Ichiji Ito and T. Nishida at almost the same time as myself in the 

 different parts of our country. In November 1901 Shotaro Hori, the Phytopa- 

 thologist of tho Nishigahara Agric. Exp. Station, published his investigation on the 

 disease in the Bulletin No. 18 of the Station. In his work he stated that the 

 injury of the fungus extends to grown rice plants and he chose a new Japanese 

 name of more extended meaning "Hagare" the leaf rot of the rice plant. For 

 the name of the fnugus he adopted the name I had given before. 



The following is the resume from my paper in the Bulletin cited above. The 

 crop is attacked by the diseass when it is about 11.2 d.m. high. The diseased 

 plant becomes slender nud pale in color and often its leaves are streaked with white 

 lines along their midribs. Then they are marked with blackish-brown spots 

 which are whitish at the centre and irregularly elliptical in shape. As the 

 diseased spots increase both in number and size, the plants grow yellowish in colof 

 and begin to die from the tip of the leaf. On the dead leaves the velvetty fertile 

 hyphae appear clearly to the nacked eye, The disease begins from a small 

 portion of a nursery plot and spreads in a wider circle. In the discolored tissues of 

 the diseased leaves, the fungus hyphae with rich contents are found in abundance 



