BULLETIN 1063, U. S. DEPARTMENT OF AGRICULTURE. 



TableS. — Relation of cut or bruising injury to the keeping quality of sioeet 



potatoes. 



[Shrinkage and decay averages for three varieties kept at a temperature 



1917-18 and 1918-19.] 



:>f 50° to 55° F., seasons of 





Average 



weight at 



harvest 



time. 



Shrink- 

 age dur- 

 ing 

 curing, 

 19 days. 



Shrinkage at end of — 



Weight 



at end of 



storage 



period. 



Loss due to decay, 

 164 days. 



Variety and 

 condition. 



51 

 days. 



82 

 days. 



111 



days. 



141 

 days. 



164 

 days. 



Uninjured: 



Big-Stem Jersey. 

 Nancy Hall . 

 Southern Queen. 



Pounds. 

 142. 56 

 140. 00 

 153. 09 



Per 

 cent. 

 6.59 

 7.14 

 7.83 



Per 

 cent. 

 8.02 

 8.46 

 9.12 



Per 

 cent. 

 9.42 

 9.69 

 10.49 



Per 

 cent. 

 10.88 

 11.03 

 12.00 



Per 

 cent. 

 12.09 

 12.12 

 13.21 



Per 

 cent. 

 13.54 

 13.10 

 14.69 



Pounds. 

 123. 25 

 121. 56 

 130. 59 



Pounds. 

 1.81 



.84 

 .59 



Per 



cent. 

 1.27 

 .60 

 .38 



Total 



435. 66 















375. 41 



3.25 







7.23 



8.55 



9.88 



11.33 



12.49 



13.83 



.75 







( 





Injured, cut, and 

 bruised: 

 Big-Stem Jersey. 

 Nancy Hall 

 Southern Queen. 



73.25 

 46.06 

 71.97 



14.44 

 18.52 

 12.55 



19.75 

 21.51 

 14.67 



23.59 

 23.88 

 16.54 



27.09 

 26.19 

 18.64 



30.33 

 27.99 

 20.05 



33.83 

 29.51 

 21.88 



48.47 

 32. 47 

 56.53 



20.16 

 4.28 

 1.94 



27.52 

 9.29 

 2.69 



Total 



191. 28 















137. 47 



26.38 







14.83 



18.26 



21.01 



23.69 



25.91 



28.13 



13.79 













Every potato in the damaged lots was either cut or bruised. Table 

 3 shows that for every period the shrinkage of the injured sweet 

 potatoes was much greater than that of the uninjured ones. The 

 exposure of the cut surfaces and the drying up of the decayed sweet 

 potatoes caused a higher shrinkage in the injured lots. At the end 

 of the storage period the average shrinkage of the three varieties 

 was 28.13 per cent for the injured and 13.83 per cent for the un- 

 injured potatoes. The Big-Stem Jersey variety showed the highest 

 percentage of shrinkage and also the largest proportion of decay 

 in the injured lots. The Southern Queen had the smallest percent- 

 age of shrinkage of the injured lots. The extent of decay was con- 

 siderably greater in the injured than in the uninjured lots. The 

 average loss for the three varieties was 0.75 per cent in the unin- 

 jured lots and 13.79 per cent in the injured lots. The greatest loss 

 was in the Big-Stem Jersey, being 27.52 per cent in the injured lot 

 in comparison with 1.27 per cent for those not injured. The propor- 

 tion of decay in the injured lot of the Southern Queen variety was 

 very small, being only 2.G9 per cent, or less than one-third as much 

 as in the Nancy Hall and less than one-ninth as much as in the Big- 

 Stem Jersey. It is a matter of common observation that the South- 

 ern Queen will stand rough handling better than any of the other 

 standard varieties. The cut surfaces of this variety heal rapidly 

 under good storage conditions. It should not be inferred, however, 

 that great care in handling it is not important, for under less favor- 

 able conditions the loss might be much higher. The excessive shrink- 

 age and the poor appearance of the injured potatoes reduce their 

 market value materially and are of sufficient importance to justify 



