SUNFLOWER 



SWEET-POTATO 



613 



broad beans and corn. The corn and beans are 

 harvested when the corn in the ear is beginning to 

 glaze. Fifty pounds of this mixture may take the 

 place of the corn silage in the ration, using about 

 four pounds less grain than ordinarily goes with 

 the corn silage. [See Bean, Broad, p. 212.] 



OU. — The small-seeded variety is preferred for 

 the manufacture of oil. When cold-pressed, a yel- 

 low, sweet oil is secured that is considered equal 

 to olive or almond oil for table use. If this resi- 

 due or " oil-cake " is warm-pressed it yields an oil 

 that is useful for lighting purposes, and for wool- 

 len-dressing, candle- and soap-making. The per- 

 centage of oil ranges from 15 to 28. 



Medicine. — Sunflower seed also has some medici- 

 nal use. When ground and mixed with other food 

 products and fed to animals it improves their 

 digestion and keeps them in good physical condi- 

 tion. The ground seed is said to be used exten- 

 sively as an important constituent of condition 

 powders and stock-foods. 



Paper and fiber. — Sunflower stems are used for 

 fuel, though they would make excellent paper stuff 

 and yield a fine fiber if industries were developed 

 thus to utilize them. 



Commercial status of the crop. 



Up to this time sunflower seed has been used 

 mainly for poultry food and in the manufacture of 

 stock-food. For these purposes the limited amount 

 grown has usually found a ready sale at an aver- 

 age price of about two cents per pound. Sunflow- 

 ers may be grown at about the same cost per acre 

 as corn, but by the methods now employed the har- 

 vesting and threshing of sunflower seed is a rather 

 slow and expensive process, and until better meth- 

 ods and improved machinery for handling the crop 

 are secured, it is not practicable to grow sunflow- 

 ers on a large scale. 



Literature. 



The best publication on the sunflower which the 

 writer has seen is Bulletin No. 60 of the Division 

 of Chemistry, United States Department of Agri- 

 culture. This bulletin has been used in the prepa- 

 ration of this article. 



SWEET-POTATO. Ipomaa Batatas, Poir. (Con- 

 volvus. Batatas, Linn. Batatas eduLis, Choisy.) 

 Convolvulacecs. Figs. 838-847. 



By M. B. Waite. 



The sweet-potato is an edible tuberous root, 

 much valued in this country, especially in the 

 southern .states, where it is a staple. It is used 

 chiefly for human food as a table vegetable, for 

 canning and for pies. It is more valuable for 

 stock-food than the Irish potato because of its high 

 content of fat, sugar (4-6 per cent) and starch 

 (16-18 per cent). Hogs can be turned in the patch 

 and will root out the sweet-potatoes for themselves. 

 The sweet-potato is sometimes fed to cattle and 

 horses, for which purpose it is sliced. 



This plant belongs to the morning-glory family. 

 The trailing vine closely resembles some of the 



Fig. 838. 

 Flowers and leaf of sweet- 

 potato [Ipomcea Batatas). 



wild species, especially Ipomaea pandurata, and it 

 is difficult to distinguish the latter when it grows 

 as a weed in the sweet-potato patches. The flowers, 

 which are rarely produced in the North, resemble 

 very closely those of the common varieties of 

 morning-glory, but are smaller. The leaves are 

 ovat3-cordate, usu- 

 ally angular or 

 lobed, petioled and 

 exceedingly varia- 

 ble ; the peduncles 

 equal or exceed the 

 petioles, several- 

 flowered, the corol- 

 las one to two 

 inches wide. The 

 flowers are pur- 

 plish, 3 or 4 on 

 each peduncle or 

 branches of the 

 peduncle; stamens 

 5 ; pistil 1, ripening 

 into a pod with 

 four 1-seeded cells. 

 The nativity of 

 the sweet-potato is 

 unknown, but it is 

 probably tropical America. It was cultivated in 

 the tropics of both hemispheres when authentic 

 records began. DeCandolle inclines to an American 

 origin. The species Ipornma Batatas is nowhere 

 known in a wild aboriginal state ; it has been sug- 

 gested that it may be a derivative of some other 

 species, as I. fastigiata. Saff ord saw models of the 

 sweet-potato in the pre-historic Yunta graves of 

 Ancon, Peru, which exhibited the pentagonal form 

 often seen in certain varieties. 



Distribution. 



The sweet -potato is essentially an American 

 crop, but it is now in cultivation in many of the 

 islands of the Pacific. Some of the varieties in 

 cultivation in the United States have come back 

 from China. Commercially, the northern limit of 

 sweet -potato -culture on the Atlantic coast of 

 America is about the middle of New Jersey. This 

 line, extended westward, barely takes in southern 

 Ohio and Kansas. At Muscatine island in the Missis- 

 sippi river and in certain other warm, sandy soils 

 from there southward, a few districts compete with 

 the southern growers. Sweet-potato-culture practi- 

 cally disappears on the Rocky mountain plateau 

 and the arid regions of the West, except in irri- 

 gated sandy soils far to the southward, as in 

 southern New Mexico, Arizona and in California. 

 The crop is grown extensively in southern Cali- 

 fornia under irrigation, both in the Imperial val- 

 ley and in the Los Angeles district. It is also 

 grown under irrigation on some sandy soils of the 

 lower San Joaquin, especially near Merced and At- 

 water, and to a limited extent at other points in 

 the great interior valley of California. The crop 

 does not appear to be adapted to the cool nights 

 and dry atmosphere of the Rocky mountain plateau, 

 or the great basin, or even in the higher parts of 



