CHEMISTRY OF THE POTATO. 139 



nine inches apart in the rows than at wider intervals. 



Fourthly. Increasing the intervals at which sets are planted, even 

 of the largest size, in the rows to more than twelve inches diminishes 

 the crop, and wider intervals induce no increase in the weight of the 

 individual sets. 



Fifthly. It may be broadly stated that the weight of the crop 

 is proportionate to the weight per acre of the sets, and the small 

 sets will produce the same crop as an equal weight per acre of large 

 sets. The fact is, however, of limited application, as a weight of 

 ver}' small sets equal to a weight of full-sized potatoes could not be 

 got into the ground except by planting them so close as to be prejudi- 

 cial to the crop. The advantage, therefore, of large sets remains 

 unimpaired. 



Sixthly. Weight for weight cutsets produce as nearly as possible 

 the same weight per acre as whole potatoes ; but for the reasons given 

 above the weight of the sets should not be reduced by sub-division. 



Seventhly. Smaller sets give a larger produce in proportion to their 

 weight than the laro;er sets. 



Eighthly. When the intervals between the sets in the rows are 

 diminished to less than a foot, the produce of each individual set is 

 proportionally diminished. Though this is not necessarily accom- 

 panied by a diminution of the weight of the crops, no increase in 

 the produce of each individual set is caused by placing the sets at 

 wider intervals than a foot. 



Hellriegel found as the result of his experiments that it was imma- 

 terial whether whole or cut potatoes were used for seed, provided, 

 equal weights were planted on equal areas. The same authoritj' found 

 that large sets gave larger yields of potatoes than small sets where 

 the same number of sets were planted on equal areas. 



Lehmann and Ulbricht found that the whole potatoes gave larger 

 potatoes than cut sets, but less in number and that the weight of the 

 harvested potatoes was less when cut potatoes were used for seed, 

 while the number of potatoes was greater. 



The average of eleven trials at the Maine State College, reported 

 by Professors Farrington and Jordan, was in favor of large potatoes 

 for seed. 



The experiments of Prof. Alvord and Mr. Emery at Houghton 

 Farm, running through two years, with several varieties of potatoes, 

 gave results favoring the use of large potatoes for seed. 



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