CHAPTER VIII 

 DISEASES OF THE SWEET POTATO 



The sweet potato grower has to contend with com- 

 paratively few diseases that could not be prevented or 

 cured if a little time and labor were expended. The 

 small farmer is chiefly troubled by storage rots, while 

 the large grower, who has a dry house which will largely 

 prevent these rots, will have to fight diseases in the 

 field. 



The practice of selling in the fall as soon as pota- 

 toes are harvested has been brought about by the con- 

 ditions prevailing in the " bank " or " pit." Farmers 

 have been accustomed to rush their product on the 

 market before the fatal rot sets in. It is estimated that 

 only about 50 per cent of the potatoes produced are 

 consumed; the other 50 per cent decaying from some 

 one of the storage rots. 



In the field some of the diseases can be destroyed by 

 spraying, but in certain cases crop rotation, change of 

 seed or draws and good cultural methods are the only 

 control measures that can be advised. 



The sweet potato troubles may be divided into the 

 following general classes: Seed and draw-bed; field 

 diseases, of tuber, stems and leaves ; storage rots ; decay 

 from mechanical causes as age, frost, excessive heat and 

 cold, handling at harvest, culling and grading for ship- 

 ment. 



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