250 FIELD CROPS 



price. The price which can ordinarily be expected for flax- 

 seed varies from $1 to $1.50 per bushel. The average acre 

 value usually ranges from $8 to $10, though in recent years 

 it has been slightly higher. This is for the seed alone. 

 Where there is a demand for the straw, this brings in some 

 additional return. As flax is ordinarily grown with very 

 little expense, there is a reasonable profit in the crop. 



309. Diseases and Insect Enemies. The principal 

 disease which attacks flax in this country is flax wilt. It is 

 this disease which commonly causes the condition known 

 as " flax-sick soil," though other fungous diseases produce 

 the same result. Flax wilt is a fungus which enters the 

 young plant, from spores either in the soil or on the seed. 

 The fungus grows inside the tissues of the plant and fills the 

 cells, causing the plant to die as if from lack of water. The 

 plants are attacked at all stages of growth, from young seed- 

 lings to maturity. The best preventive measures are to sow 

 only clean seed from which all dirt and pieces of flax straw 

 have been removed, to treat the seed with the formaldehyde 

 solution (Sec. 205), and to grow flax on new land only, or 

 as a single crop in a rotation of several years' duration. 

 Much can also be accomplished by saving seed from plants 

 which mature in flax-sick soil and hence are resistant to the 

 disease. Manure containing flax straw or from stock fed 

 on flax straw should not be put on land on which flax is to be 

 grown. Several other fungous diseases occur, but most 

 of them are similar to flax wilt, though of a less serious 

 nature, and yield to the same treatment. The crop is not 

 subject to serious injury from insects. 



310. Place in the Rotation. On account of the fungous 

 diseases which attack flax when it is grown for several years 

 on the same land, rotation of crops is particularly essential 

 if this crop is to become a permanent one in any locality. 



