THE POTATO 431 



The furrows may be opened up a few days in 

 advance of the planting, so that warm soil will 

 surround the seed when it is dropped. The seed 

 should be dropped by hand and carefully covered 

 with a shovel plow or ridger. 



As soon as the first crop is out of the ground, the 

 ground should be thoroughly worked in prepara- 

 tion for the second crop, if another crop of po- 

 tatoes is to follow. If potatoes are to follow grain 

 or some other crop the ground should be deeply 

 plowed and a good seed bed made. The ground 

 is warm at this time, so that no sprouting of seed 

 is necessary before planting. Seed from the pre- 

 ceding crop, or northern-grown seed that has been 

 kept dormant in storage may be used. 



Cultivation should begin soon after the seed is 

 planted. The first cultivation should be deep, 

 to thoroughly open up a deep root nest in which 

 the tubers are to form. On irrigated land the 

 high ridge system of growing potatoes is usually 

 used, because it makes it possible for the po- 

 tatoes to develop in a loose, open, well-aired soil, 

 the moisture supply coming through the bottom 

 of a fairly deep furrow into the base of the ridge 

 and being drawn up by capillarity. 



The number of irrigations, and the number of 

 cultivations, must be determined by the needs of 

 the soil and the growing plant. No fixed rule can 

 be set, because conditions may change daily. 

 Irrigation water must be used with sufficient fre- 

 quency to furnish all the moisture the crop needs. 

 Too much is as bad or worse than too little. A 

 shortage of moisture makes a short crop. Cul- 

 tivation is required as often as is necessary to keep 

 the soil open and mellow. 



In the Sacramento Valley the first crop starts 



