38 A PLANT-DISEASE SURVEY IN TEXAS. 



Root-rot {Ozonium omnivorum Shear). — This trouble caused the 

 death of a. large portion of a plat of snap beans in a truck garden 

 in a single locality. Black-eyed peas occupied an adjacent plat, and 

 the disease affected portions of both, beginning at the end and ad- 

 vancing to form a distinct semicircular area, about half of the semi- 

 circle being occupied by each species. 



Specimen collected: Uvalde, 1944. 



Root-rot {Rhizoctonia sp.).— A few plants of " frijole " beans in 

 an in*igated field were affected with this disease. 



Specimen collected : On Brack ranch, 30 miles west of Cotulla. 2185. 



Rust {Uromyces a'ppendiculatus (P.) Lk.).— This disease was ob- 

 served in an irrigated truck garden, and also in the University garden 

 at Austin. The maximum development of the trouble was not 

 reached till after most of the crop had been harvested, so that only. 

 a small amount of loss resulted. 



Specimens collected: Uvalde, 1947, 1948; Austin, 3129. 



BEET. 



Leaf -spot {Cercosj)ora heticola Sacc.).— The presence of the sub- 

 circular, dry, pallid blotches on the leaves of the beet {Beta vulgaris 

 L.) was very commonly observed. The disease was not, hoAvever, 

 sufficiently alDundant to cause a great amount of injury. 



Specimens collected : Austin, 369, 1322, 1429, 3042 ; San Antonio, 1376, 3177 ; 

 New Braunfels, 1716; Sabinal, 1967; Georgetown, 2366. 



Root-knot {Heterodera radicicola (Greef) Mill.).— This trouble 

 was quite common, especially in irrigated gardens or low moist 

 ground, but was not serious. 



Specimens collected: Austin, 3137; San Antonio, 3148. 



CABBAGE. 



Leaf -spot {Cercospora hloxami B. and Br. (?)).— The fungus 

 which is the cause of this leaf -spot on the cabbage {Brassica oleracea 

 r-apitata L.) produces pale, subcircular areas 1 to 5 mm. in diameter 

 surrounded by a slightly raised, faintly purple border. Conidial tufts 

 amphigenous, more conspicuous in the center of the spots. Conidio- 

 phores densely tufted, pale brown, sparingly septate, 60 to 120 by 

 4 to 4.5 /x. Conidia long-clavate, ta^^ering, straight or much cui^red, 

 hyaline or faintly smoky, many septate, 3 to 5 by 100 to 270 fx. Our 

 specimens are somewhat doubtfully referred to this species, since the 

 published descriptions include no infoiTuation ronceniing size of 

 conidiophores or spores, and the original specimens showed no 



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