The Bulletin. 35 



SWEET POTATOES. 



Being a semitropical plant and requiring a long growing season free 

 from frost, the sweet potato is preeminently a southern crop. In the 

 South the moist, sugary potatoes commonly termed "yams" are grown 

 almost exclusively for table use, while in the North and West the dry 

 varieties of the "Jersey" type are wanted. Potatoes grown for market 

 should be of such varieties as each particular market demands. 



A larger number of marketable sweet potatoes can be produced on 

 moderately fertile land than on very rich soil made up largely of or- 

 ganic matter. A light, well-drained sandy loam on which a crop of 

 cowpeas has been grown the previous season is a good place for sweet 

 potatoes. This will usually supply most of the nitrogen necessary 

 for the potato crop. An excess of nitrogen will cause a rank growth of 

 vines, with small, stringy potatoes. The soil should be plowed and pul- 

 verized thoroughly to a depth of 5 or 6 inches. Deeper preparation 

 often allows the potatoes to become .long and ill-shaped. This is 

 immaterial if the crop is used for stock feeding, but if intended for 

 market purposes the rather thick, spindle-shaped potato is preferable. 



The most common method of propagating sweet potato plants is to 

 place the tubers close, without touching one another, in a hotbed or, 

 later in the season, in a cold frame, and cover them with about 3 inches 

 of sand or loose sandy loam, a month or six weeks prior to the time 

 for setting out plants. Use clean sand if possible, as there is less 

 likelihood of its harboring diseases that might prove destructive to 

 the young plants. Keep the bed moist and exposed to plenty of sun- 

 light to hasten the development of sprouts from the bedded potatoes. 

 These sprouts put out roots and so become individual plants ready to 

 be transplanted to the field. Another method of propagation sometimes 

 employed is to make cuttings from vines already growing in the field 

 and plant them the same as "sprouts." 



In transplanting sweet potatoes, set the plants a little deeper than 

 they were in the plant-bed, so that no part of the stems that were pro- 

 tected by earth in the bed will be exposed in the field. Plants are set 

 either in checks 2 feet each way or about 15 inches apart in rows 3 

 feet apart. If the weather is dry the plants should be watered as soon 

 as convenient after planting. When planting is done in sunshine or 

 wind, the vitality of the plants is often saved by puddling the roots. 

 This is done by dipping them in a batter of the consistency of cream, 

 made of clay and water. Transplanting machines, provided with water 

 tanks from which each plant is watered automatically as it is set, can 

 be used to advantage in planting extensive areas. These machines can 

 be used for setting all kinds of vegetable plants, tobacco, etc., and are 

 provided with attachments for planting Irish potatoes and for distrib- 

 uting fertilizers. As soon as the plants have taken root, cultivation 

 should begin. Continued shallow workings should be given until the 

 growth of vines makes further cultivation impracticable. 



