12 BULLETIN 1063, U. S. DEPARTMENT OF AGRICULTURE. 
The loss due to decay in this experiment was very small, the 
average being only 1.10 per cent for all varieties. Among the 
varities tested, those showing the greatest loss were the Gold Skin, 
8.66: Big-Stem Jersey, 3.65; Pumpkin "Yam," 2.64; Haiti, 
2.45 ; and Red Brazil. 2.18 per cent. Of the 27 varieties in the ex- 
periment 4 showed no decay ; 7 varieties had a loss between 0.02 and 
0.25 per cent; 6 varieties between 0.25 and 0.50 per cent; 1 variety 
0.72 per cent; 4 varieties between 1 and 2 per cent, and the others 
showed losses between 2.18 and 8.66 per cent. 
The conditions in the storage room were nearly ideal; therefore 
the loss due to decay was so slight that differences between varieties 
mean very little. 
Several varieties, chiefly those belonging to the Jersey group, 
namely, Red Jersey, Big-Stem Jersey, Yellow Jersey, and Gold 
Skin, though not showing excessive decay, had begun to deteriorate 
and from a commercial point of view should have been removed 
sooner. 
COMPARISON OF THE KEEPING QUALITIES OF SWEET POTATOES 
WHEN STORED AT DIFFERENT TEMPERATURES. 
To determine the effects of different temperatures on the keeping 
qualities of sweet potatoes, experiments were conducted during 
1917-18 and 1918-19. Three standard varieties of sweet potatoes 
were stored in each of three different rooms, where after the cur- 
ing period it was the plan to maintain the temperature between 50° 
and 55° F., 55° and 60° F., and 60° and 65° F.. respectively. The aim 
during curing was to keep the temperature high enough to cure the 
potatoes properly, all three rooms being treated alike. After the 
curing period the temperature Avas gradually lowered in each room 
and an effort made to maintain it between the points mentioned. The 
average weekly temperature usually varied only a few degrees, as 
shown in figure 1. 
The shrinkage of sweet potatoes at the end of the curing period 
and at various intervals during storage and the percentage of loss 
due to decay are shown in Table 6. 
Table 6 shows that under all temperatures about half the shrink- 
age occurred during the curing period. After the curing period the 
shrinkage continues, but the rate is rather slow, averaging less than 
1| per cent a month under the three sets of temperatures. Comparing 
the average percentage of shrinkage under the three different tem- 
peratures, it is seen that it is greater at the higher temperatures. The 
difference between the first two sets is especially noticeable, and is 
just as noticeable with the Big-Stem Jersey and Nancy Hall varieties 
in the third set. The Southern Queen showed less shrinkage at 60° to 
65° F. than at any other temperature. The average total shrinkage of 
