THE FIBER CROPS 351 



370. Insects and diseases. The cotton grower must 

 contend with numerous injurious insects and diseases. The 

 most common and injurious insects are the boll weevil and the 

 boll worm, which do considerable damage to the crop in many 

 sections of the cotton region. The boll weevil is a small insect, 

 about one-half inch long, which lays its eggs in the bolls soon 

 after the blossoms fall. The larvsB which hatch from them eat 

 out the center of the boll. The most effective means now known 

 of combating them is the removal of the affected bolls and their 

 destruction, and the growing of early varieties which mature 

 before the insects become numerous. 



The cotton boll worm is closely related to the corn ear worm, 

 and affects the cotton plant by eating the leaves and the im- 

 mature seeds in the boll. The same methods as were recom- 

 mended for the control of the boll weevil may be employed to 

 control the boll worm. Sometimes arsenical poisons may be 

 sprayed on the affected plants with good results. The important 

 diseases of cotton are the wilt and the root rot. Rotation of 

 crops is recommended as the most effective means of controlling 

 them. 



FLAX 



Flax culture begins with the recorded history of the 

 Egyptians and the Hebrews, who used this fiber in the 

 making of clothing, many years before the dawn of the 

 Christian era. So far as is known, its original home was 

 somewhere in the eastern Mediterranean country, whence 

 it was introduced into Asia and Europe and later was 

 brought to the United States. For many years it was 

 grown only for the fiber, but more recently the value of 

 the seed as a source of oil has brought about the rapid 

 increase of its culture in many places for this purpose. 



371. Description. Flax, Linum usitatissimum, be- 

 longs to the Linaceae or Flax family, of which it is the 

 most important species. One or two other species are 

 cultivated to a small extent in some parts of the world, 

 and several grow wild both in America and Europe. Flax 



