Jan. 15, 1921 Tubers, Skins, and Sprouts of Potatoes 627 



April, 19 19, the sprouts constituted 13.33 P er cent °f the total moist 

 weight of sprouts, skins, and tubers. These plants had been sprayed 

 with 5-5-50 Bordeaux. 



The Rural New Yorker tubers (samples 10, n, and 12) and the Green 

 Mountain tubers (samples 13, 14, and 15) were grown at Foxcroft, Me., 

 and had been sprayed with 5-5-50 Bordeaux spray. At the time of 

 analysis, April, 19 19, the sprouts of the Rural New Yorker tubers, a late 

 variety, constituted 3.5 per cent and the Green Mountain sprouts 7.2 

 per cent of the total moist weight. These two varieties of tubers, dug 

 from the same field late in September, 19 18, were stored in the laboratory 

 under identical conditions. 



Samples of Green Mountain potatoes from Connecticut (samples 18 

 and 19), as well as the Irish Cobbler tubers grown in Maine (sample 21), 

 were held at laboratory temperature until June, 1919, when the sprouts 

 and tubers were analyzed separately. While the sprouts of the Irish 

 Cobblers were large and fresh, those of the two samples of Green Moun- 

 tain potatoes were partially dried and withered. No analyses of the 

 skins were made for these three samples analyzed in June because of 

 the difficulty of paring the soft tubers. 



The variations in the percentage composition of sprouts obtained from 

 tubers stored under identical conditions can be explained only on the 

 basis of the presence in varying amounts of growth-promoting substances 

 in the different varieties of tubers. 



COMPOSITION OF SPROUTS AND TUBERS 



The analytical data in Table I include the distribution of nitrogen in 

 terms of total nitrogen. The total weight and percentage distribution of 

 the ash, phosphoric acid, and nitrogen compounds present in the sprouts 

 and tubers are given in Table II. Table III shows the ash, phosphoric 

 acid, and nitrogen results on a water-free basis. 



