EXPERIMENT STATION BULLETINS. 351 



Depth of Planthiff 



The depth of planting will be governed mostly by the character of the 

 soil, and by the time of planting. For the late crop on the lighter types of 

 soil the sets are placed to a depth of 4 to 6 inches, while on heavy soils a depth 

 of 3 to 4 inches is sufficient. In very early planting the depth should be 

 less than in late planting because of colder soil and weather conditions. 



It is important that the seed pieces be placed sufficiently deep to be in 

 cool, moist soil and so that they will not be disturbed by subsequent tillage 

 with a spike-tooth harrow or weeder. 



Plan t iiig D is ta n ca 



The natural fertility of the soil, together with its moisture-holding ca- 

 pacity, will determine largely the distance of plantmg. On fertile soils that 

 are well supplied with humus, potatoes can be planted closer than they can 

 on soils that are deficient in plant food and humus. Early varieties of pota- 

 toes are generally planted somewhat closer than late varieties, since the vine 

 growth of the early kind is not usually as large as that of late varieties. 

 High price of seed may act as a factor in causing a wider spacing of the plants. 



On the lighter types of soils it is quite a common practice in this state to 

 plant potatoes in check rows that are 36 " x 36 " apart. This method is exten- 

 sively used by growers who plant with the hand planters and who dig the 

 crop with forks. On land that is infested with quack grass or Canada thistles 

 it is much easier to keep the field clean by cultivating both ways. The 

 practice of planting in check rows is not generally recommended. When 

 the plants are spaced so far apart they are likely to develop oversized, rough 

 tubers that in many seasons are hollow. When soil conditions permit, it is 

 better to plant the potatoes in drills, with the rows approximately 36 inches 

 apart, and the hills 12 to 24 inches apart in the row, depending upon the 

 fertility of the soil. The drill method of planting generally produces a larger 

 yield of medium sized, marketable potatoes and reduces the amount of over- 

 sized tubers. In tests conducted in Wexford county on light soils where 

 plots planted 36" x 36" were compared with plots planted 36" x 18", the 

 closer planting gave an increased yield of 38 bushels per acre. The potatoes 

 from the closer planting were also of much better market quahty. 



The amount of seed required to the acre depends upon the distance of 

 planting and the size of the seed piece. With rows 36" x 36" apart, if seed 

 pieces averaging one and one-half ounces are used, approximately 8 bushels of 

 seed to the acre will be required. Approximately 15 bushels of seed cut to 

 one and one-half ounce seed pieces will be needed to plant an acre when the 

 rows are 36" apart with the hills 18" apart in the row. 



Plcmtinf/ Tools 



On land that is free from stumps and large stones, machine planters will 

 prove very satisfactory. They will deposit the seed at a uniform depth and 

 will cover it at once with moist soil so that it will not dry out. Where a 

 grower plans to grow five acres or more of potatoes, he is usually warranted 

 in buying a planting machine, which will enable him to plant four or five acres 

 of potatoes a day. 



There are two general types of machine planters. The one-man or picker 

 type in which the seed is automatically picked up and dropped by forks that 

 are attached to a revolving vertical disk, and the two-man or platform type 



