12 BULLETIN 721, U. S. DEPARTMENT OF AGRICULTURE. 



In the irrigated sugar-beet areas usually less than 20 inches of 

 moisture falls during the entire year, and frequently many of the 

 showers are so light that they are of no practical benefit in crop pro- 

 duction. Sugar-beet growers in those sections depend largely upon 

 irrigation. Frequently the showers that fall in irrigated areas are 

 detrimental rather than helpful in the production of sugar beets, 

 since they frequently cause the soil to crust. If this crusting occurs 

 shortly after the seed is sown the young plants have great difficulty in 

 breaking through to the light, with the result that the stands are 

 very seriously injured and replantings are necessary. If the show- 

 ers occur soon after the beets are up and the ground crusts around 

 the young plants, the air is cut off from the roots and growth is 

 interfered with. This may sometimes be remedied by prompt culti- 

 vation, although the plants are often so firmly embedded in the crust 

 that cultivation is difficult without serious injury to the plants. 

 Sometimes a moderately heavy roller of one of the types shown in 

 Plate II will produce the desired result in breaking the crust. In 

 icrigated sections every effort should be made to retain the fall or 

 winter moisture in the soil, and if the ground is dry in the fall, 

 irrigation is generally desirable. The soil should be sufficiently 

 moist when the seed is planted to produce prompt and complete 

 germination, and there should be sufficient moisture in the soil to 

 maintain a steady growth for several weeks. As soon as the plants 

 indicate that they are suffering from lack of moisture they should 

 be irrigated. When beets wilt during the day and fail to revive at 

 night they should be watered without delay. Usually from one to 

 three irrigations during the growing season are sufficient to produce 

 a crop in most of tlie irrigated sections where sugar beets are grown. 

 When beets are irrigated the soil should be thoroughly wet, and every 

 effort should then be made to retain the moisture as long as possible 

 by frequent cultivation. 



Sunshine. — The third element of climate which has a marked ef- 

 fect on the quality of sugar beets is light, over which man has little 

 control except in the selection of locality. It is generally believed 

 that direct sunshine is an important factor in the production and 

 storage of sugar in the beet. Observation indicates, however, that 

 diffused light is almost, if not quite, as effective in producing and 

 storing sugar as direct sunlight. The importance of light should not 

 be overlooked, however, since without it the leaves could not manu- 

 facture sugar. Beet sugar is all made in the beet leaves by the action 

 .of light upon the leaf green when moisture and carbonic-acid gas 

 are present. Without light this action in the leaf can not take place, 

 no matter liow favorable may be all other conditions for growth and 

 sugar production. 



