274 CULTURE OF IRISH POTATOES 



terminal buds start, and the seed is usually planted whole. This 

 method is used where a very early crop is desired, especially when 

 the planting is done in a cold, wet soil, where seed is likely to rot. 

 Frequent experiments in comparing sprouted or greened seed with 

 dormant seed have usually shown a decided increase in favor of the 

 former. This is especially true with early planting in cold, wet soils. 

 Amount of Seed to Plant. In order to give an idea about how 

 much seed is required to plant an acre, the following table is given. 

 The rows are assumed to be three feet apart : 



Bushels of Seed Required Per Acre 



Size of seed piece 



Ounces Hills 12 inches apart Hills 18 inches apart Hills 24 inches apart 



1 16 12 8 



2 32 24 16 

 4 64 48 32 

 8 128 96 64 



In general, growers in the United States use from 12 to 15 

 bushels of seed per acre, while in Europe they frequently plant 30 to 

 40 bushels of seed. 



Many experiments have shown that the total yield will increase 

 with rate of planting up to 30 to 40 bushels of seed per acre. How- 

 ever, the percentage of small potatoes also increases with rate of 

 planting under average conditions, and only the most favorable 

 climate and soil justify the heavier planting. 



Under average conditions from 15 to 20 bushels of seed per acre 

 will give the maximum yield of marketable potatoes, and as condi- 

 tions are improved above the average, the planting should be in- 

 creased. This is illustrated by the following experiment (Ohio 

 Bui. 218) : 



Relation Between Amount of Seed and Yield of Large and Small Potatoes 



Yield per acre 



Seed, bushels Marketable Small Net marketable 



Size of seed per acre bushels bushels above seed 



planted, bushels 



One 'eye 10 164 25 154 



Two eyes 15 204 31 189 



One-half tuber .... 25 217 35 192 



Whole tuber 40 223 51 183 



It was also shown at the Ohio Station that certain varieties 

 develop more sprouts from the same sized seed piece than others and 

 consequently require less seed. For example, the maximum yield 



