264 



>iew Jersey Experiment Station, Dr. Hilsted describes nine 

 fungous diseases of the sweet potato. It is probable that 

 many of them also occur in this state. Some of them only 

 attack the stored potatoes, others attack the foliage, while 

 still others live on the vine through the summer and cause 

 a destructive rot of the stored potatoes in winter. The 

 Black-rot (C''rfi(o'-i/sfi.sJJmbriafn) is of this class and is per- 

 haps the worst of sweet potato diseases. It first appears 

 on the potatoes as dry sunken dark-colored spots. If anv 

 such diseased potatoes are bedded in the spring, the fungus 

 will attack the draws or shoots forming black spots on the 

 stems. Such draws are said to have "black-shank" and if 

 planted will certainly produce diseased potatoes in tlie fall. 

 This may not sliow much when dug but it will develop 

 later and the the rot will spread to neighboring sound po- 

 tatoes in the bin. This shows the necessity for bedding 

 none but perfectly sound potatoes. This .disease seems to 

 be able to live over for some time in the soil so when it is 

 detected it is unwise to replant the sam3 land to sweet pota- 

 toes for a year or two at least. 



Much of the loss in the stored sweet potatoes from the 

 other rots can be avoided by greater care in di"-eiuff and 

 handling. Cut and bruised sweet potatoes never keep well 

 and when freshly dug they are very easily injured. The 

 common practice of picking thefn up in sacks after digging 

 always bruises them badly. Smooth shallow boxes holding 

 half a bushel to a bushel should be provided for this pur- 

 pose and they should be emptied carefully so as to avoid 

 letting the potatoes fall any distance. In fact they should 

 be handled as carefully as eggs ia order to keep well. If they 

 are stored in bins or cellars it is important to clean these out 

 thoroughly and disinfect by burning sulphur and white- 

 washing before storing another crop. Some very favorable 

 results are reported from dusting the potatoes as they are 

 stored with a powder prepared by slaking lime with water 

 in which copper sulphate has been dissolved. 



