CULTIVATION AND IRRIGATION 69 



is well to use the cultivator as much as possible, as the hoe 

 cuts and bruises more small tubers than the cultivator, if 

 handled properly. When the soil has a great amount of 

 weeds, the field may be harrowed just before and after the 

 plants are up, and cultivated well; then the weeds may be 

 kept in check without a great amount of hand labor. 



Some potato growers believe that a small amount of 

 cultivation after the plants are up is all that is necessary, 

 but I have learned that the more frequent the cultivations, 

 without destroying the vines, the better. When the tops 

 have grown too large to cultivate without tearing them it is 

 best to discontinue this kind of cultivation. However, if the 

 weeds still persist, then the hoe may be used. The weeds 

 should have been destroyed before this time, as they use up 

 the moisture and plant food rapidly. 



Potatoes, when irrigated, do not have the good quality 

 as when grown in a naturally moist soil, although the larger 

 acreage devoted to potato culture in California is irrigated. 

 When it is necessary to irrigate, those irrigated by capillary 

 attraction are of much better quality than those that are 

 soaked or flooded. 



In the warm climates, where irrigation is necessary be- 

 fore the plants are up, a deep furrow should be made in the 

 center of the rows to run the water in so that the moisture 

 may be drawn up by capillary attraction, making the hills 

 in a comparatively loose open ridge. The furrows in the 

 center of the rows insure even cultivation. In such warm 

 climates the soil should be irrigated very lightly just after 

 planting, as the moisture in the soil may have evaporated to 

 a certain extent during cultivation. After this light irriga- 

 tion, when the soil is dry enough not to stick, cultivate well 

 and near the hills. This kills the weeds that may have start- 

 ed by irrigating. Each cultivation after the first should be 



