334 FIELD 'AND GARDEN PRODUCTS 



,hown that if very small cuttings are used, and if the soil is fertile, 

 the distance can be reduced to 6 or 9 inches without sacrificing the 

 yield, provided the season happens to be favorable, but this is not 

 generally advisable. 



On rich soil cuttings of considerable size can be advantageously 

 planted as close as 12 inches. Checking effects a saving of labor in 

 cultivation, and also in planting and harvesting, when these latter 

 operations are performed by hand ; hence expensive labor and the ab- 

 sence of machines for planting and harvesting the crop are condi- 

 tions in favor of checking. For planting in checks a variety can be 

 chosen which makes a large growth of vines and which forms many 

 tubers in each hill, thus more completely utilizing the space at its 

 disposal than could a variety with small vines and few tubers. In 

 checking there is danger on rich soil that some of the tubers may 

 grow to an objectionable size. Potato growers in attempting to ob- 

 tain a phenomenal yield, as in contests for prizes, almost universally 

 plant in drills rather than in hills, and place the seed pieces from 8 

 to 15 inches apart. The advocates of planting in drills claim that by 

 this method a larger yield can be obtained, and experience seems to 

 confirm the correctness of this view. The few experiments that have 

 been made on this question are not entirely conclusive, though the 

 majority of them favor drills. Although no fixed rule regarding dis- 

 tance of planting can be given, the following general considerations 

 are widely applicable: 



(1) For maximum yield of salable potatoes plant in rows as 

 narrow as can be conveniently cultivated. 



(2) Crowd small seed pieces close together in the row, increas- 

 ing the distance with every increase in the size of the seed piece; 

 avoid on the one hand such close planting as to greatly reduce the 

 average weight of the tubers, and on the other such wide spacing as 

 to leave any considerable portion of the soil unshaded by the full- 

 grown vines. 



(3) As a rule, the richer the land the less the required distance 

 between sets. 



(4) Varieties with strong growth of vines or which set many 

 tubers in a hill should have greater distance between plants than is 

 necessary with less vigorous varieties. 



Cultivation. Soon after planting, and again just as the young 

 plants are beginning to appear above ground, the field should be 

 narrowed, inclining the teeth of the harrow backward. This is a 

 cheap method of cultivation, since a wide space is covered. It is also 

 effective in destroying small weeds, in leveling the ridges left in 

 planting, in preventing the formation of a surface crust, and in 

 keeping the land covered with a mulch of dry earth, thus conserving 

 moisture within the soil below. Subsequent cultivation should be 

 frequent so as to accomplish these same ends. Almost any pattern of 

 cultivator may be used, provided it is made to do shallow work. 

 However, if the ground has become packed the first cultivation may 

 be deeper. Experience and exact experiments generally favor flat or 

 nearly flat cultivation. Excessive hilling during cultivation intensi- 



