cultural directions 
467 
When roots of uniform size and high quality are de- 
sired for market, it is much better to sow in drills, so 
that cultivating, weeding and thinning can be properly 
attended to. 
666. Fertilizing. — See notes for beets (323). 
667. Harvesting. — See notes for beets (325). 
668. Enemies. — Club root is the most serious disease. 
See notes on club root of cabbage (367). Maggots are 
also destructive sometimes. The application of corro- 
sive sublimate is the most effective treatment (133). 
Lice often become serious pests and are difficult to control 
since they feed on the undersides of the leaves. Turnips 
should be grown in rotation with the noncrucifers to 
avoid losses from the attacks of insects and dis- 
eases. 
WATERMELON (Citrullus vulgaris) 
669. History. — The watermelon is native to Africa and 
has been cultivated since remote antiquity. Although 
a popular dessert vegetable in many parts of the world, 
it has met with greatest favor in the United States. 
670. Importance. — The watermelon is an important 
crop in every southern state and from some sections of 
the South it is shipped north in enormous quantities. 
Arizona and other western states are developing the in- 
dustry. All of the northern states produce this cucurbit 
to some extent. It might be grown more largely, how- 
ever, in the less favorable parts of the country were 
proper cultural methods adopted. 
671. Varieties. — Rane (N. H. Sta. Bui. 86, p. 95) pre- 
pared a system of classification which should be familiar 
to students of vegetable gardening. The analytical key 
contains the following six classes, according to the color 
or markings of the skin: (1) Light Green Class, (2) 
Medium Green Class, (3) Dark Green Class, (4) Light 
