A PLANT-DISEASE SURVEY IN TEXAS. 33 



DISEASES OF SMALL FRUITS. 

 BLACKBERRY. 



Leaf -spot (Septoria rubi Westd.). — This disease was observed in 

 only two localities, as the blackberry (Rubus sp.) is not commonly 

 cultivated in this section. The foliage was very copiously spotted. 



Specimens collected : Llano, 1765 ; Floresville, 2857. 



DEWBERRY. 



Leaf -spot (Septoria rubi Westd.). — This fungus produces on the 

 dewberry {Rubus sp.) purple-margined, grayish-centered spots, 1 to 

 2 mm. in diameter. It is abundantly present everywhere on both 

 wild and cultivated forms. 



Specimens collected: Austin, 375, 1268, 1318; San Antonio, 1364, 3150; 

 Brenham, 1464; Boerne, 1658; New Braunfels, 1693; Luling, 2271; Seguin, 

 2323 ; Georgetown, 2360 ; Victoria, 2514 ; Gonzales, 2675 ; Flatonia, 2728. 



Leaf-spot (Cercospora rubi Sacc). — Large, brown, irregularly out- 

 lined areas characterize this disease. It is perhaps as generally pres- 

 ent as the other leaf-spot and as destructive. 



Specimens collected: Elgin, 1871; Bastrop, 2058; San Marcos, 2116; Luling, 

 2246 ; Round Rock, 2411 ; Victoria, 2504 ; Nursery, 2554 ; Cuero, 2594 ; Flatonia, 

 2728; Yoakum, 2763; Hallettsville, 2782. £ 



GRAPE. 



Black-rot (Guignardia bidwellii (Ell.) Viala and Eavaz). — This 

 is the most common and most destructive disease of the grape (Vitis 

 spp.). On the leaves it produces conspicuous, circular, brick-red 

 spots, 2 to 8 mm. in diameter. Embedded in these areas are the black 

 pycnidia. It also occurs very abundantly on the fruit, and in sev- 

 eral cases observed the crop was a total failure, leaving dry, wrinkled 

 mummies in place of the normal fruits. It was observed on several 

 varieties of cultivated grapes, among them Thompson's Seedless and 

 the Mission, also on several wild species, as Vitis cinerea Engelm., 

 V. candicams Engelm., and V. monticola Buckl. 



Specimens collected : Austin, 1276, 1326, 1412, 1560, 3056, 3062 ; San Antonio, 

 1336, 1391; Brenham, 1463; Hempstead, 1499; Kerrville, 1622; Boerne, 1645; 

 Beeville, 1815, 1834, 1835 ; Bastrop, 2047 ; Luling, 2231, 2255 ; Georgetown, 2382 ; 

 Round Rock, 2405 ; Gonzales, 2665 ; Flatonia, 2717 ; New Braunfels, 1696 ; Elgin, 

 1880 ; Lockhart, 2084 ; Yoakum, 2758 ; Hallettsville, 2776. 



Downy mildew (Plasmopara viticola (B. and C.) Berl. and De 

 T.). — A white, downy coating is produced in spots on the under sur- 

 face of the affected leaves. It is not at all common in this section, 

 having been observed but once. 



Specimen collected : Austin. 



100833° — Bull. 226—12 3 



