POTATO. 191 



from scab as can be obtained; put the seed potatoes into 

 bags, either before or after cutting- them and then dip them in- 

 to the corrosive sublimate solution and allow them to 

 stay in it for an hour and a half. If seed potatoes are treated 

 in this way and then planted on land free from scab, the re. 

 sultant crop will seldom be seriously injured, by scab. The 

 expense of this treatment including- labor should not exceed 

 one dollar per acre. 



Blight of potatoes is a disease which attacks the leaves and. 

 stems of potatoes, and sometimes even the tubers are affected. 

 It is most prevalent during moist, warm weather, when some- 

 times the fungus may be seen as a delicate white mildew on the 

 stems and leaves of the potato vines. In seasons favorable to 

 it, the tops of an entire field may be killed in a few days from 

 the time the disease was first noticed: at other times, the tops 

 die so gradually it is mistaken for a natural dying of the 

 vines. Rotting of the tubers often follows the dying of the tops. 

 It has been quite clearly shown that this disease may be kept 

 in check, or the trouble entirely prevented, by spraying the 

 tops with the Bordeaux mixture occasionally. It is, however, 

 somewhat doubtful about the benefits being sufficiently certain 

 in this section to justify the expense; but should this disease be- 

 come more abundant it may prove to be a paying operation. 

 The cost of treating one acre with the Bordeaux mixture is 

 about $5.00. There is little use of applying this material 

 after the damage from the disease is apparent, as it must be 

 used as a preventive. 



Bordeaux Mixture is made as follows: Dissolve five pounds 

 of blue vitriol ( sulphate of copper ) in a wooden or earthen- 

 ware vessel. As this substance dissolves very slowly in cold 

 water and solutions of it are very heavy, it is well to suspend 

 it near the top of the water. (It dissolves more quickly 

 in hot water.) In another vessel, slake five pounds of good 

 fresh quicklime in ten gallons of water. When the mixture is 

 wanted, pour the blue vitriol into a barrel containing- thirty- 

 five gallons of water and then add the lime. When thoroughly 

 stirred, the color of the mixture should be a clear sky blue. 

 After being mixed for a day or so the mixture loses much of its 

 strength, so it is well to use a supply that has been mixed 

 only a short time previously. There are many formulas 



