34 U. S. DEPARTMENT OF AGRICULTURE. 



CUCUMBER: MOSAIC. 



Cause : Unknown. 



Cucumbers affected with mosaic may be variously mis- 

 shapen, often bearing large warts. They are often dis- 

 tinctly mottled in color. A common type is a combination 

 of green warts on a white or yellowish background. 



Mosaic is a widespread and very destructive disease of 

 the vines which greatly reduces the yield. It is extremely 

 communicable and is spread by insects. 



Usually the more severely affected fruits do not reach the 

 market. So far as known, the edibility and keeping quali- 

 ties of affected fruits are not impaired, but the market value 

 is materially lowered. 



No practical control is known. 



Ref. (13); (22); (31). 



CUCUMBER: SCAB. 



Cause: A fungus (Cladosporium cucumerinum). 



The symptoms of this disease on the fruits are small, cir- 

 cular, sunken lesions covered with a greenish velvety 

 growth of mold. Drops of a red gummy exudate may be 

 formed on these spots. The disease is not simply a scab as 

 the name would imply, since the tissues are rather deeply 

 involved. 



The fungus attacks the vines, and fruit infection occurs 

 in the field. Young growing parts are very subject to 

 attack. The disease is very important in the pickle crop, 

 where it becomes severe late in the season. It is favored 

 by cool, moist weather. 



Ref. (12). 



CUCUMBER: SUN-SCALD. 



(See Sun-Scald). 



EGG PLANT: FRUIT ROT. 



Cause: A fungus (Phomopsis vexans). 



At first fruit rot consists of small, circular or oval spots. 

 Usually the lesions are at first much lighter in color (tan or 

 gray) than the surrounding tissue. Later the lesions become 

 dark brown and sunken, and under favorable conditions 

 increase very rapidly in size. By the coalescence of such 

 lesions, much or all of the surface of a fruit may be involved. 

 Small, brown to black, pimple-like pustules or pycnidia 

 break through the surface and cover the inner and older 

 zones of affected tissue. The affected regions are brown 

 and softened. At times they are quite dry, suggesting a 

 dry rot. 



Fruit rot occurs in all egg plant growing regions, but is 

 especially severe in the South. 



The disease occurs on the plants in the field, where it 

 attacks leaves, stems, and fruit, and is known as leaf spot, 



