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 carbolic 

 acid emulsion is the most effective treatment (133). The 

 emulsion is injected into the soil about the roots. This 

 is rather tedious and expensive to practice on a large 

 commercial scale. Turnips should always be grown in 

 rotation with the noncrucifers to avoid losses from the 

 attacks of insects and diseases. 



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: (i) Light Green Class, (2) 

 Medium Green Class, (3) Dark Green Class, (4) Light 



