1925 Volume 1 Issue 6 Pages 1-14_1
1. Purple speck, or “Shihan”, is caused by a fungus which is new to science. The name, Cercosporina Kikuchii, is suggested for this organism.
2. The fungus also attacks leaves, stems and pods to a certain extent.
3. When the fungus is grown on the glucose media, it turns the solutions purple. This mycelial extraction in water also exhibits a similar color, which is insoluble in ether, petrol ether, chloroform, benzine, terpentin oil and carbon bisulphide. This pigment becomes red with acid, and exhibits pale greenish discoloration, when the solution is added with alkali and left for a few minutes.
4. Myceliai extraction in alcohol exhibits bright red color, which becomes rich green with. alkali and red with acid. This pigment is soluble in ether, chloroform, acetone and terpentin oil, but insoluble in benzine, carbon bisulphide, petrol ether and water.
5. It seems that the early varieties are more susceptible than the late ones. It is also noticed that the varieties of big beans are more or less susceptible as compared with those of the smaller beans.
The authors wish to express their heartiest thanks to Dr. S. Hori for many valuable suggestions