Family Leguminos^e 261 



there are found indefinite yellow spots or blotches. 

 On the leaves the trouble appears as watersoaked 

 spots which later are amber colored (fig. 46 a). On 

 the stems and pods (fig. 46 b) a canker is formed 

 which somewhat resembles the canker produced by 

 Colletotrichum lindemuthianum. From the stem the 

 disease works down to the main root, causing it to rot. 



The Organism. Pseudomonas phaseoli is a short 

 rod rounded at both ends, motile by means of polar 

 flagella. It liquefies gelatin slowly, coagulates milk, 

 and the whey separates slowly with acidity. 



Control. The same as for anthracnose, p. 265. 



Streak 

 Cause, Bacterial. 



Streak is a disease which is little known. It has 

 been recently studied by Sackett, ' although the cause 

 has not been definitely determined. The trouble 

 may perhaps be the same as the streak of the sweet 

 pea, caused by Bacillus lathyri Manns and Taub. 



Streak attacks stems, leaves, and pods (fig. 46 d,e) 

 of the bean plant. On the pod and on the leaves the 

 disease appears as peculiar rusty to orange brown 

 spattered spots which run down in streaks. Dis- 

 eased foliage drops off prematurely, giving the plant 

 a denuded appearance. For methods of control, see 

 bean anthracnose, p. 265. 



Damping Off, see Pythium, p. 43. 



Downy Mildew, see Lima Bean, p. 267. 



1 Sackett, W. A., Colorado Agr. Expt. Sta. Bui. 226 : 27, 1917. 



