34 A PLANT-DISEASE SURVEY IN TEXAS. 



Leaf -spot {Cercospora mticola (Ces.) Sacc). — This fungus causes 

 the formation of large, dark-brown, almost black, spots on the upper 

 surface of the leaf which show below as much fainter brown areas. 

 They are somewhat circular in outline and 2 to 10 mm. in diameter. 

 (PL VIII, fig. 2.) The conidia formed on the lower leaf surface 

 are clavate, more or less curved, brown, and 42 to 60 bv 5 to 7 \i. 

 (PL III, fig. 8.) ^ 



It becomes very abundant in the late summer, causing the leaves 

 to be badly spotted and producing considerable defoliation. The 

 disease is present on both wild and cultivated forms. 



Specimens collected : Austin. 251 ; Tyler, 1551 ; Boerne, 1645 ; New Braunfels, 

 1695; Llano, 1762; Beeville, 1864; Bastrop, 2027; San Marcos, 2108; Luling. 

 2250; Seguin, 2306; Victoria, 2513; Nursery, 2561; Cuero, 2591; Stockdale, 

 2633; Gonzales, 2657, 2692; Flatonia, 2732; Hallettsville, 2777, 2791, 2793; 

 Floresville, 2852. 



Sooty mold {Fumago vagans (?) P.). — The upper leaf surface is 

 coated over with a black, sooty covering. Observed in only a single 

 locality. 



Specimen collected : Luling, 2263. 



STRAWBERRY. 



Leaf-spot {Mycosphaerella fragariae (Tul.) Lindau). — When the 

 spots first appear on the leaves of the strawberry {Fragaria sp.) they 

 are brownish or reddish, becoming circular, 3 to 6 mm. in diameter, 

 with a dead white or grayish center and a broad, purplish margin. 



Specimens collected: Austin, 1314; Beeville, 1845. 



DISEASES OF TRUCK CROPS. 

 ASPARAGUS. 



Blight {Cercospora asparagi Sacc). — On the cladophylls and 

 branches of asparagus {Asparagus officinalis L.) diffuse grayish- 

 brown spots are produced. Densely clustered over these areas are 

 dark fascicles of conidiophores and conidia. Large branches, espe- 

 cially on the older parts of the plant, are killed. 



Specimens collected: Victoria. 2505; Floresville, 2853. 



Rust {Puccinia asparagi DC). — The rust of asparagus was ob- 

 served in only one locality. This can be explained by the fact that 

 asparagus is rarely cultivated in the territory covered by this 

 survey. 



Specimens collected : Austin, 383, 1916, 2946. 



BEAN. 



Antliracnose {C olletotrichum lindernKthianum (Sacc. and ]\fagnus) 

 Briosi and Cav.) — The anthracnose is generally prevalent on beans 



226 



