THE BEAN BLIGHT! TYPE 



2s;> 



vain, however, in the Paris markets in 1913. The same year 

 at the International Exposition in Milan in the exhibit of the 

 French Mycological Society I saw a yellow bacterial culture on 

 slant agar, marked "La Graisse, " which was, perhaps, Bac- 

 terium phaseoli. It was made by Dr. T. A. Cordier of Rheims. 

 The disease has been reported from South Russia by Spieshnev 

 and from Japan by Arata Ideta who says : "This disease heavily 

 damaged in Ishikari, Hokkaido, in 1903.' 



Reinking has recently 



reported it from the Philippines 

 (Phytopathology, vol. 9, 1919, p. 

 131) where it is said to be "common 

 and destructive." Miss Doidge 

 writes me (1919) that it is quite 

 common in South Africa. 



Cause. This disease is due to 

 Bacterium phaseoli EFS. This is a 

 yellow, non-viscid or slightly viscid, 

 motile, polar flagellate (Fig. 227), 

 non-capsulate, non-sporiferous, Gram 

 negative, liquefying (both gelatin 

 and L6 frier's blood serum), aerobic, 

 non-gas-forming, non-nitrate-reduc- 

 ing, starch-destroying, dry-air toler- 

 ant, sunlight-sensitive (Fig. 228), 

 frost-sensitive (in bouillon), single, 

 clumping, catenulate, or filamentous 

 schizomycete which grows on agar- 

 poured plates in the form of small 



FIG. 218. Earliest stage of 

 visible bean pod spot. Two in- 

 fections each central through a 

 single stoma. Plant sprayed 

 Dec. 14 1914, and confined for 

 19 hours in a roomy cage. 

 Photographed Dec. 22. X 10. 

 The organism used was a 72- 

 hour agar-streak culture of the 

 Idaho bean germ after reisola- 

 tion from a plant successfully 

 inoculated on Sept. 23. 



circular, or nearly circular, smooth, pale yellow, entire-margined 

 colonies, becoming deeper yellow with age (denser and deeper 

 yellow than those of Bacterium malvacearum) and then often 

 pale ringed. Gelatin and Lo frier's solidified blood serum are 

 liquefied rather freely. Milk is curdled by means of a lab fer- 

 ment, tyrosin being formed. The first evidence of curdling is the 

 appearance of a shallow layer of clear whey above the slowly 

 settling mobile curd. No acid is formed in milk. The organism 

 resists drying. It grows feebly in Cohn's solution and in Uschin- 

 sky's solution. The thermal death-point is approximately 50C. 



