584 



FIELD AND GARDEN PRODUCTS 



southern South America has been obtained. So far as known the 

 first specimens of yautia to reach Asia (Singapore) or Australia 

 (Ipswich, Queensland) were distributed by this station. And it ap- 

 pears that, although more readily propagated, more productive, and 

 fully as palatable as the taros, which probably originated in the same 

 region, the yautia has unaccountably remained exclusively a tropical 

 American plant. The usual method of harvesting yautia is by hand 

 pulling, supplemented by the use of the hoe. In loose soil one man 

 can gather the tubers from 5 to 10 plants per minute; that is, 1,000 

 to 2,000 pounds of tubers per hour. The leaves are usually left at- 

 tached to the root for some days after harvesting; then they 

 are cut off about 4 to 8 inches above the top of the old root, which is 

 thrown into a pile to await planting time, or if for market the fine 

 roots are trimmed off and merely the tip is reserved for the seed pile, 

 while the edible portion is sold along with the tubers. While single 

 plants may yield as high as 6 or more pounds of tubers, the average 

 for common varieties in ordinary soil may be reckoned at 2 to 3 

 pounds per hill. With 10,000 plants per acre this gives 10 to 15 tons 

 of roots per acre. To this may be added 5 to 8 tons of the "madres," 

 which in several varieties are sold for table use and which may be 

 utilized as a source of starch or for fattening swine and poultry. 



Composition. Analyses of two samples of yautia have been 

 made at the Maine Experiment Station, and the results given below 

 are quoted from unpublished material. A white variety contained 

 85.9 per cent edible portion and 14.1 per cent refuse, i. e., parings. A 

 yellow variety contained 76.9 per cent edible portion and 23.1 per 

 cent refuse. In the preparation of ordinary Irish potatoes and sweet 

 potatoes for the table, the edible portion constitutes on an average 80 

 per cent and the parings or refuse 20 per cent of the tuber. The fol- 

 lowing table shows the composition of the two varieties of yautia 

 analyzed, calculated to a uniform basis of 70 per cent of moisture, 

 and includes for purposes of comparison the composition of Irish 

 potatoes and sweet potatoes: 



The analyses show that yautias do not differ materially in com- 

 position from the potatoes. As is the case with potatoes, carbohy- 

 drates constitute the chief nutritive material. An examination of the 

 yautias shows that the principal carbohydrates present is starch. 



Summary. The planting of yautias, taros, and dasheens should 

 be begun as soon as the danger from frost is over, for they require 

 six months or more tp mature. It is native to tropical America and 



