DISEASES OF TKUCK CROPS. 43 



SPINACH. 



Leaf-spot (Cercospora beticola Sacc.). — This fungus on spinach 

 (Spinacia oleracea L.) forms numerous subcircular areas, 1 to 3 

 mm. in diameter, with a slightly raised margin. The dark, amphi- 

 genous conidiophores cause the larger part of the diseased area to be 

 brown. No record has been found of the occurrence of a Cercospora 

 on this host, but as the symptomatology and size of conidiophores and 

 spores are similar to C. beticola, and as the hosts are closely related, it 

 is in all probability the same species. 



Specimen collected: Austin, 3039. 



SQUASH. 



Anthracnose (Colletotrichum (?) nigrum Ell. and Hals.). — This 

 fungus was found on squash (Cucurbit a spp.) in the same field with 

 the Colletotrichum, which was attacking sweet peppers, and agrees 

 with it morphologically. From this it may be inferred that it is 

 probably the same. On the fruits are formed numerous dark acer- 

 vuli, often concentrically arranged. 



Specimen collected: On cymling (Cucuroita pepo L.) — Uvalde, 1941. 



Fruit-rot (Botrytis cinerea P.). — In one field the young fruits were 

 seriously affected with this fungus. It apparently starts on the de- 

 caying flower and in a few days the entire fruit is destroyed and 

 covered by a black 5 fungous growth. (PL X, fig. 3.) 



Specimen collected: On cymling (Cucuroita pepo L.) — Austin. 



Leaf -spot (Macrosporium sp.). — Eounded dry areas surrounded 

 by an area of yellow are formed on the leaves. The center may be- 

 come grayish with age. We were not able definitely to associate the 

 fungus with any given species. 



Specimen collected: On cushaw (Cucuroita moschata Duch.) — Beeville, 1840. 



Leaf -spot (Cercospora cucurbitae Ell. and Ev.). — Rounded brown 

 spots 1 to 4 mm. in diameter, becoming whitish with an elevated 

 border, appear on the foliage. The characters of the conidiophores 

 and conidia agree with the original description (IT), except in size, 

 the conidiophores being sometimes 150 jx long and the conidia reach- 

 ing 300 ix and being plainly multiseptate. 



Specimen collected: On cushaw (Cucuroita moschata Duch.) — Hempstead, 

 1498. 



Rhizoctonia root-rot (Corticium vagum B. and C. var. solani 

 Burt). — A very considerable loss in an irrigated field was due to this 

 fungus, the entire root system being destroyed. 



Specimen collected: On cymling {Cucuroita pepo L.) — San Antonio, 3151. 



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