POTATO GROWING. 321 



seed is plowed in- to a depth of four to eight inches, ac- 

 cording to season and soil, a thorough cross-harrowing 

 should leave the field in good shape. On light soils dis- 

 posed to be dry, a light rolling may be beneficial. As soon 

 as the plants appear harrowing with the rows mellows the 

 surface, kills small weeds, and does not hurt the potatoes. 

 Cultivation between the rows should follow when the 

 plants are up about three inches, and the surface should 

 be kept loose until the plants are quite high. Good, clean 

 culture is the rule with potatoes. In some soils, not dis- 

 posed to dry out too rapidly nor to crust, crops are often 

 made with little cultivation after weeds stop growing, 

 especially where the plant has the benefit of coast influ- 

 ences, but cultivation for moisture retention, where needed, 

 must be more thorough. 



On lands subject to excess of moisture, winter growth of 

 potatoes can be facilitated by the ridge planting described 

 in the chapter on Cultivation, but where this is not likely 

 to occur, flat culture is best, both in winter and summer. 

 Where potatoes are to be irrigated a slight moving of the 

 soil toward the row, so as to make the interspace a little 

 hollow to carry water, is admissable, but "hilling up" is 

 unnecessary and dangerous. It usually uncovers the firm 

 soil and exposes the roots to too great heat and drought. 

 It is also likely to bring the tubers within reach of the 

 moth from whose eggs come the potato worms. During 

 the latter part of the growth the tuber should be well cov- 

 ered with soil. 



Irrigation. The potato should be kept growing thriftily 

 from start to finish. If growth is arrested by drought, a 

 new growth of small potatoes is apt to start upon renewal 

 of moisture, to the detriment of the crop. The aim should 

 be, then, to keep the soil adequately moist by constant cul- 

 tivation or by irrigation until maturity approaches. Irri- 

 gation is best done by running small streams between the 

 rows, the planting having been arranged for this distribu- 

 tion. As already stated, excessive irrigation is decidedly 

 detrimental to the quality of the crop, and extra effort 



