40 A PLANT-DISEASE SURVEY IN TEXAS. 



Root-rot {Rhizoctonia sp.). — The plants which are affected remain 

 dwarfed for a time and then wilt and die. The stems up to the 

 gTound level and a little above are sunken and have little wartlike 

 nodules. The loss was quite serious in an irrigated garden where it 

 was observed. 



Specimen collected: San Antonio, 1329. 



GLOBE ARTICHOKE. 



Leaf -spot {Cercospora ohscura Heald and "Wolf, 32). — The pres- 

 ence of this disease on the globe artichoke {Cynara scolymus L.) 

 is made manifest by the circular gi*ay spots, varying in diameter 

 from 1 to 2 mm., which appear on the upper surface of the leaf in 

 great numbers. Each spot has a faint brown border, with the tufts 

 of conidiophores on the upper surface. Since the lower surface of 

 the leaf is covered by a silvery tomentum the spots appear as slightly 

 darker areas. 



The conidiophores are in groups of from four to seven, epiphyl- 

 lous, nonseptate, varying in length from 50 to 80 ju, and in width 

 from 4 to 5 ju, brown, with a hyaline tip. The conidia are cylin- 

 drical in shape, 40 to 74 by 3 to 4 ju,, three to four sei>tate, dilutedly 

 colored, and straight or curved. (PI. Ill, fig. 6.) 



Specimen collected: Beeville, 1861 (type specimen). 



MUSKMELON. 



Anthracnose {C olletotrichum lagenarmm (Pass.) Ell. and Hals). — 

 The appearance of large, dead, brown patches on the leaf of the musk- 

 melon {Cucumis melo L.) marks the presence of this fungus. 



Specimen collected : Beeville, 1827. 



Leaf -blight {Alteimaria hrassicae (B.) Sacc. var. nigrescens 

 Pegl.). — Large brown spots are formed on the foliage, attaining 1 cm. 

 in diameter. "VVlien numerous the leaves turn brown and curl. It 

 was observed to be sufficiently abundant in one field to cause a very 

 serious loss, and has been reported to be a very destructive blight 

 south of our territory. 



Specimens collected : Austin, 1425, 3136 ; Hallettsville, 2904. 



Root-knot {Ileterodera radicicola (Greef) Miil.). — This trouble 

 was observed in an irrigated garden where the plants remained 

 stunted for a time, and at length succumbed. The crop was an 

 entire loss. (PL IX, fig. 2.) 



Specimens collected : San Antonio, 1327 ; Austin, 3135. 

 226 



