MARKET DISEASES OF VEGETABLES. 73 



infection in the case of the stem-end rot found in the market 

 takes place through the end of the stem after it is cut. The 

 rot then develops with extreme rapidity during transit. 



This is the most important rot of watermelons, and is 

 rather general in southern grown stock, causing very heavy 

 losses in some cars. 



Stem-end rot as it occurs in transit can be prevented by 

 proper treatment of the melons at the time of loading. After 

 a tier of melons is in place, the ends of the stems are cut off 

 and a paste made of starch and copper sulphate is applied 

 to the freshly cut surfaces. This prevents infection by the 

 fungus. 



Ref. (42); (51). 



WATERMELON: MISCELLANEOUS DISEASES. 

 BLOSSOM-END ROT. 



Cause: Unknown (not parasitic). 



This disease appears as a flattened, dry, leathery, black- 

 ened spot about as big as a silver dollar, at the blossom-end 

 of the fruit. The tissues underneath are sound unless the 

 killed area becomes infected with some fungus such as the 

 Diplodia of stem-end rot, which is a common secondary 

 invader. 



While the cause of this trouble has not been demon- 

 strated, it is quite likely that it is due to an unbalanced 

 water supply as in the similar disease of tomatoes. Although 

 of minor importance in the market, it may .open the way to 

 rot-producing fungi. 



Ref. (51). 



CHEMICAL INJURY AND ABRASION. 



Cause : Contact with the walls or floors of cars. 



This injury consists of large brown sunken areas or 

 gouged channels in the rind. It is most common in cars 

 previously used for chemicals such as fertilizers, especially 

 where some shifting of the load has occurred. Sometimes 

 fungi gain entrance through these injuries, and cause decay. 



Compared with stem-end rot, this trouble is not of com- 

 mon occurrence. 



Ref. (51). 



