3OO THE FORAGE AND FIBER CROPS IN AMERICA 



the leaves of mangel-wurzels or rutabagas. Yields of four 

 tons of tops per acre are reported. 



V. MINOR ROOT CROPS 



382. PARSNIPS (Pastinaca sativa L.) require similar conditions, for their 

 best development, to carrots. The cultural methods of carrots and parsnips 

 are substantially alike, and similar difficulties in raising them are encountered. 

 Parsnips are well liked and sometimes recommended for dairy cattle. The 

 low yield, however, appears to preclude their general use. Unlike most other 

 roots, they are improved rather than injured by freezing, and may be left in 

 the ground until spring. 



383. CASSAVA (Manihot utilissima Pohl.) AND SWEET CASSAVA (M. palmata 

 var. aipi Mill. Arg.). "A native of the tropics, but recently introduced in 



Louisiana and Florida. On 

 fertile soil it is said to yield 

 as much as 10 tons of roots 

 per acre, and the roots are 

 worth fully as much as pota- 

 toes for feeding. The plant is 

 propagated by planting short 

 cuttings of the stems, and re- 

 quires only ordinary cultiva- 

 tion. As the roots decay 

 quickly after being taken out 

 of the ground, they should be 

 dug only as wanted for use. 



384. CHINESE YAM (Dios- 

 corea divaricata Blanco; D. 

 batatas Decne). "The roots 

 are quite large, club-shaped, 

 often reaching three feet in 

 length with a diameter of three 

 inches at the lower end. They 

 are starchy and mucilaginous, 

 and make a food fully as rich 

 Hollow crown parsnip as sweet Potatoes, but their 



peculiar shape makes them 

 hard to dig. The plant is 



propagated by means of small tubers, which are produced in immense numbers 

 in the axils of the leaves, and on a rich loamy soil the yield of these tubers 

 is often 50 or more bushels per acre. These tubers remain on the surface of 

 the ground uninjured during ordinary winters, and so are a valuable winter 

 food for hogs. 



385. CHUFA (Cyf>crus csculcntus L.). "A perennial sedge that produces 

 a large yield of small tubers which are valuable food for hogs.. It grow? 



