in rows 5 to 6 feet apart with seed pieces 3 to 4 feet 
apart in the rows. 
Cover the seed pieces to a depth of 4 inches except in 
certain arid regions at high altitude where the surface 
soil dries out quickly. Under such conditions plant 5 
inches deep. 
If the crop is grown for its tubers, leave the tops un¬ 
disturbed until they are killed by frost. 
Follow artichokes next season with a late-sown 
quick-growing hay crop or cultivated crop. Plow deep¬ 
ly and thoroughly when volunteer artichokes are a foot 
or more high. Hand-pull the survivors, unless they will 
be destroyed by harvesting the crop in which they are 
growing before August. 
LEVULOSE SUGAR 
Of the many plants which yield levulose, the Jerusa¬ 
lem artichoke (Helianthus tuberosus) has long been 
known to be the hardiest and most prolific. The plant 
lends itself readily to mechanized agriculture. The 
yields reported for the different varieties range from 
10 to 20 tons per acre. The levulose content varies from 
7 to 24 per cent. The artichoke is said to produce more 
sugar per acre than any other plant except sugar cane, 
while the cost of production per acre is less than for 
any other sugar-yielding plant. 
At Iowa State College, the Dubrunfaut method has 
been adopted for the separation of levulose from the 
Jerusalem artichoke. However, important modifica¬ 
tions have been made which in the opinion of the 
writers make the process really commercially possible. 
Levulose possesses unique properties which will make 
its introduction into our list of available sugars invalu¬ 
able. These properties have been widely discussed in 
the scientific and popular literature until an almost 
ready-made demand awaits the advent of levulose. 
Chief among its possible uses is to supply the desire 
for a sweet and the necessity of carbohydrate to the 
ever increasing number of those suffering from dia¬ 
betes. The high solubility of levulose makes it valuable 
for cold drinks. It has been used for infant feeding, 
since it is one of the most easily digested sugars. It 
prevents the crystallization of other sugars in its 
presence, and therefore might be used to prevent this 
from occuring in jellies, in honey and in ice cream. The 
fact that it is the sweetest of all sugars should make 
it ideal for the confectionery industry, where alone or 
in combination with other sugars it should make any 
