186 Root Crops 



the plants are well established. It is mostly a succession- 

 crop. 



Carrots are sown in drills from 10 to 18 inches apart, de- 

 pending largely on the variety and the method to be employed 

 in tilling. The early crop is thinned to 4 or 5 inches in the 

 row, and the late large varieties to about 6 or 8 inches. Rows 

 are 10 to 16 inches apart, or twice this distance for horse till- 

 age. If it is not desired to plant the late varieties for autumn 

 use, one may choose the early varieties for that purpose, sowing 

 the seed late in July or even the first of August. Unless the 

 soil is in very fine tilth and moist, however, it is difficult to 

 secure a stand as late in the season as this. Carrot seed 

 should always be sown thickly to allow for any failure in 

 germination. It is sown about % or % inch deep. For an acre, 

 2 to 3 lbs. of seed are required; for 300 feet of drill, 1 oz., 

 if the seed is fresh. Good crops run 200 to 400 bu. to the 

 acre, and in special cases^ more than this if the very large 

 kinds are grown. 



Stobage rot (Sclerotinia libertiana). — Frequently carrots in 

 storage show a soft rot over which there later appear white 

 felts of mycelium containing hard black fungous bodies. These 

 black bodies or sclerotia serve largely to carry the fungus over 

 winter. Control: Carrots should not be grown on land in- 

 fested with the organism. The removal of affected plants in 

 a field is desirable to eradicate the fungus. Thorough drying 

 of the roots in the field, careful sorting out of decaying car- 

 rots, and storage under cool dry conditions are important. 



Caerot bust -fly (Psila roses).— A slender straw-colored mag- 

 got, fy ' in. long when mature, that burrows in the root of 

 carrots. Fortunately in this country serious attack is not 

 likely to continue in the same locality for more than one or 

 two seasons in succession. No satisfactory control is known. 



Cakrot beetle (Ligyrus gibhosus). — A reddish brown beetle 

 resembling a June beetle, about % in. long, that feeds mostly 

 underground, gnawing out holes in the roots and underground 

 stems. Control: Clean farming and a short rotation of ' crops. 



