812 



EXPERIMENT STATION RECORD. 



In 181).') at distances of 12, 24, and 30 in. between tlie plants in tlie 

 row the yields were resjx'ctively 207.(52. 2;>7.0S, and 229.75 bu. per acre. 

 When 2 slips were inserted together at distances of IS in. tlie yield was 

 greater than when 1 slip was used either 18 or 9 in. apart. Thirty- 

 three varieties are described and figured and their yields are tabulated. 

 The largest yields were made by White 8t. Uoniingo, Shanghai or 

 Clay, Boone White, and Hayman, 



"The slit-leaf varieties are ninch the most productive. . . . They are also gCD- 

 erally charncterizod by bright yellow flesh (when cooked), fineness of liber, and 

 delicacy of flavor. They are also as a rnle excellent keepers. . . . The best potato 

 in point of quality is the Georgia Yam, but it is unproductive. The best combina- 

 tion potato is probably the Tennessee Yam. It is of excellent quality and quite 

 productive." 



The composition of sweet potatoes, M. E. Jaffa and M. Curtis 

 {California ISta. Rpt. W93 and 18!)4^])p. 219-225). — Seventeen varieties 

 of sweet ])otatoes grown at the Pomona Substation were analyzed. The 

 average results for the 17 varieties are given in the table below, which 

 for comparison also contains the average results of 21 varieties grown 

 at the Texas Station. 



AualijHis of sweet poiaioes. 



Calit'oruia. Tex.as 



Water 



Ash 



Protein 



Fat 



Total sugar 



Ilitrogeii free extract 

 I'iber 



Sweet potatoes grown in Texas Avere richer in protein and sugar, 

 while those grown in California contained a larger percentage of fiber. 

 Of the 17 varieties grown in California, Bermuda contained the highest 

 percentage of protein, 3.08 per cent, and Vineless the second largest 

 percentage, 2.28. Barbadoes gave the largest content of total sugar, 

 11.55 per cent, and Red Kansemond the minimum. The varieties dif- 

 fered bat slightly in the percentage of nitrogen-free extract. 



Irish and sweet potatoes are comi)ared with reference to their nutri- 

 tive value. The potential energy in 1 lb. of Irish potatoes is calculated 

 as 375; in 1 lb. of sweet potatoes, 537. 



An analysis is given of the ash of sweet-potato roots, and on the 

 basis of this analysis it is calculated that a crop of 5,000 lbs. of roots 

 removes from the soil 31.4 lbs. of potash, 8.75 lbs. of phosphoric acid, 

 and 15 lbs. of nitrogen. 



Fertilizer experiments v^ith sweet potatoes [Neio Jersey Sfas. 

 Ii'pt. 189:-)', pp. 12.5-13(>). — On a fertile soil in Gloucester County, manured 

 the preceding year with IS tons of barnyaid manure, a sweet potato 

 exjieriment was conducted on twentieth-acre plats in 1893. Mixed 



