Family Leguminosae 271 



The Organism. Bacillus lathyri as worked out by 

 Manns, ' is rod-shaped, occurring singly, never found 

 in chains, and seldom united by twos or fours, 

 motile by means of flagella. It produces no spores, 

 no capstiles, no zooglea, liquefies gelatin completely 

 in about three weeks, and produces no gas. 



Control. Rotation of crops is helpful; but since 

 streak attacks numerous leguminous crops, such as 

 bean and clovers, these should be excluded. Other 

 methods of control are as yet unknown. 



Rust, see Bean, p. 262. 



Powdery Mildew, see Bean, p. 262. 



Angular Leaf Spot 



Caused by Cercospora cruenta Sacc. ; Cercospora 

 dolichi E. and E. 



Angular leaf spot is a common disease on cowpeas. 

 When it attacks the leaves, they are covered with 

 angularlrusty red spots, the leaves turn yellow and 

 drop prematurely. On the stems the spots are ir- 

 regular, elongated, dark colored, dightly sunken, 

 and later forming cankers. The latter often crack 

 and expose the stems to the attacks of various other 

 parasitic and even saprophytic fungi. Under favor- 

 able conditions of moisture, the spots on the leaves 

 or stems are covered with a brownish downy growth 

 made up of the conidiophores and conidia. No 

 methods of control are known. 



» Manns, T. P., Delaware Agr. Expt. Sta. Bui. io8 : 3-44, 1915. 



