No. J.] MODERN POTATO CULTURE. 47 



ment stations and by practical growers, while not always 

 uniform, in general indicate as follows regarding the care 

 and selection of seed potatoes. 



The seed should be from mature but not over-ripened 

 potatoes. It should be kept in the dark in a not too dry 

 atmosphere and as far as possible at a temperature of 33° to 

 10° F. The weight of the cutting is more important than 

 the number of eyes, i.e., the heavier the piece the larger 

 the yield. Whole potatoes give heavier crops than cut- 

 tings. In general, the "seed" ends of the tubers give 

 larger yields than the 4 ' stem" ends. While under careless 

 management northern grown seed frequently gives larger 

 yields than southern, the careful selection and storing of 

 seed are of more importance than changes of latitude. Cut 

 seed should be allowed to dry somewhat before being 

 planted. If it is to be planted soon after cutting it should 

 be covered with plaster, or some other material, to prevent 



" bleeding." 



Fertilizers for Potatoes. 



Analysis shows that the composition of potatoes, so far 

 as nitrogen, phosphoric acid and potash are concerned, is 

 fairly uniform, and that each 100 pounds of fresh potatoes 

 carry about .31 pound of nitrogen, .13 pound of phosphoric 

 acid, .48 pound of potash and .01 pound of lime. If wc 

 assume these figures to fairly represent potatoes as grown in 

 New England, a crop of 200 bushels, weighing 6 tons, w T ould 

 remove 37 pounds of nitrogen, 16 pounds of phosphoric acid 

 and 58 pounds of potash. 



If the amounts and proportions of fertilizing elements re- 

 moved by a crop could be taken as a guide in preparing a 

 field for that crop, the problem of supplying the proper 

 amount and kind of plant food to the soil would be much 

 simplified. To manure a field for a crop of potatoes, nitro- 

 gen, phosphoric acid and potash would have to be added in 

 about the proportions given above, and in sufficient quantity 

 to supply the vines and tubers the land was expected to 

 yield. A formula made up on this basis would be very 

 different from any mixed fertilizer on the market, and 

 would contain the fertilizing elements in about the fol- 



