MARKET DISEASES OF VEGETABLES. 35 



stem blight, and fruit rot. The original infection of the fruit 

 takes place in the field, but the disease develops and spreads 

 in transit and often causes heavy losses. 



It is not safe to ship spotted fruits. 



Ref. (23). 



EGG PLANT: RHIZOPUS ROT. 



(See Rhizopus Rot). 



LETTUCE: BLACK ROT. 



Cause : Bacteria. 



Black or brown spots or irregular patches on the outer 

 leaves, increasing in size under proper conditions until entire 

 leaves are involved, are the symptoms of this disease. Later 

 the inner leaves may be attacked, and a soft dark brownish 

 rot of the head may result. 



This is a field disease reported from Florida affecting 

 seedlings and older plants. It may develop during transit. 



Other bacterial field diseases of lettuce have been re- 

 ported from North Carolina and Louisiana. 



The relation of these field diseases to the slimy soft rot 

 prevalent in the market has not yet been determined. 



Ref. (60). 



LETTUCE: GRAY MOLD ROT; BOTRYTIS ROT. 



(See Gray Mold Rot and Cauliflower Gray Mold Rot). 



LETTUCE, ENDIVE, ESCAROLE, AND CHICORY: SLIMY SOFT 

 ROT; BACTERIAL ROT. 



(See Slimy Soft Rot). 



LETTUCE: WATERY SOFT ROT; SCLEROTINIA ROT; DROP; 



DAMP-OFF. 



(See Watery Soft Rot). 



LETTUCE: RUSSET. 



Cause : Not known, probably non-parasitic. 



This disease is characterized by small reddish to russet 

 spots or streaks which may occur on practically all of the 

 leaves of an affected head. The brown streaks usually occur 

 along the large veins of the leaves. The vascular bundles 

 in the stalk and in the petioles may also be discolored. 



Russet occurs in lettuce from all regions. 



Nothing is known about control of the disease. 



It is advisable to sort carefully before shipping because 

 the presence of russeted heads reduces the value of a ship- 

 ment. 



LETTUCE: TIP BURN. 



Cause: Non-parasitic (irregular water supply). 



This disease is characterized by the dead, brown borders 



