CULTURE OF THE SUGAR BEET. Ill 



Solutions of nutritive matters are considered more favorable to the 

 purpose than pure water, because the latter in prolonged soaking- will 

 often remove from the seeds some of their soluble constituents. The 

 length of time during which the soaking should be continued might vary- 

 somewhat, according to the temperature, but it is generally confined to 

 48 hours, and 24 are often considered sufficient. Basset states that 

 during 24 hours seeds will absorb — 



69 per cent, their weight of water at 39.9° Fabr. 



91 per cent, their weight of water at 50.8° Fahr. 



95 per cent, their weight of water at 60° Fahr. 



97 per cent, their weight of water at 65° Fahr. 



Experiment has shown that seeds require, in a soil sufficiently moist 

 and aerated, a total sum of degrees of average temperatures equal to 

 650 Fahr. for germination. Thus if the average daily temperature be 

 50°, 13 days will be required for germination ; if it be 55°, then 12 days 

 will suffice ; and if 6o°, only 10 days will be required. If, however, the 

 seed be soaked for 24 hours in water at 100°, then the total sum of ther- 

 mometric degrees, and consequently the number of days required for 

 germination, will be correspondingly reduced. If they be soaked 4S 

 hours at 100°, then only 9 days will be required for germination in the 

 ground at an average temperature of 50°, and a correspondingly less 

 time with a higher temperature. 



With regard to the best time for sowing them, Basset* directs as a 

 rule : "Sow as early as possible according to the temperature of your locality, 

 whatever may otherwise be the method chosen? Thus, when the tempera- 

 ture of the air is from 50° to 54° Fahr. at noon, 46° to 50° in the evening, 

 and 32° to 36° in the morning, sowing may be begun without fear of 

 unfavorable temperature. This may be combined with observations of 

 the temperature of the soil, which should at the same time have an av- 

 erage of about 45° at a depth of 4 to 6 inches. 



Concerning the depth to which the seed should be covered in the 

 ground, opinions differ somewhat, but it will naturally follow that much 

 must necessarily depend upon the temperature of the season, the phys- 

 ical condition of the soil, and the proportion of moisture. The seed re- 

 quires the presence of oxygen for germination, and, therefore, if the 

 penetration and circulation of atmospheric air be rendered difficult or 

 impossible on account of a close, hard character of the soil, this func- 

 tion cannot be exercised, and the seed will rot in the ground. If the 

 soil be permeable and contain sufficient moisture, the depth of covering 

 the seed will vary with the temperature. If this be too low, again, the 

 seed will rot. But with a favorable temperature and a good physical 

 condition of the soil, less attention may be given to the depth of seed- 

 ing. However, it is considered a good rule not to bury the seed under 

 any circumstances more than 1 to 2 inches, and experience has shown 



* Guide Pratique du Fafo'icant de Sucre, p. 387. 



