THE POTATO 403 



of the soil for working and for the early growth of 

 the potato plants. The ordinary methods of cul- 

 tivation may then be followed, without further 

 addition of water, until about the time the plants 

 blossom. At this stage of development the tubers 

 are set, and it is then that an abundance of water 

 is needed to give them good growth. After the 

 water is once apphed to the soil, it should not be 

 allowed to become dry again until time for the 

 crop to mature. If the soil is allowed to become 

 dry at any time after the first application of water 

 and a subsequent irrigation is given, the tubers are 

 sure to make a second growth and become knobby. 

 Water should not be applied too late in the season, 

 or the potatoes will not ripen properly. In all 

 applications of irrigation water, care must be taken 

 to avoid bringing it in direct contact with the 

 growing tubers, as under such conditions the ten- 

 dency for the potatoes to become scabby is in- 

 creased. 



"If winter irrigation is not practised, the first 

 water should be applied immediately after the seed 

 is planted. Irrigated potatoes should be hilled, 

 and the water applied between the rows. In ordi- 

 nary soil, water applied in the middle of rows three 

 feet apart satisfies the requirements of the grow- 

 ing potatoes. The cultivator should follow each 

 application of water. 



"'Sub-irrigated' lands, when not too wet or too 

 strong with alkali, are most satisfactory for rais- 

 ing potatoes. There are some localities where soils 

 receive just enough seepage from irrigation ditches, 

 or other water supplies, to keep in moist, friable 

 condition throughout the season. These, with 

 frequent shallow cultivation, produce the finest, 

 smoothest tubers, with the least trouble and ex- 



