342. TWENTY-FIRkST UEPUHT. 



TABLE No. 8 

 Percentages of disease found In car-lot shipments. 

 Each percentage represents a car average. 



Black Heart: 30, 5';. 



Slimy Soft Rot (Bacterial): 6. 1 Ji, 1. 1. 2, 5, 1, 15, 3, 5, 2. 6, 4, 2, 3, 1, 6. 2. 1, 4, 2, 7. 

 2, 2, 1. 9, 1 H. 4, 1, 1, 2, 1, 1. 2, 2, 3, 2, 3, 1 %. 



Fusariiim Rot: 2, 3, 5, 2, 1, 1, 1, 1, 3. 3, 3, 2, IH. 4, 2, 1, 2H, 1, 2, 3, 4, 1. 12, 12, 7. 

 2, 7, .5, 5, 3, 4, 2, 2. 2, 8, 2, 3, 2 5^, 8. 2, 2, 1, 2, 3, 1, 2, 1, 2, 3. 1. 3, 2, 3, 4. 1. 1, 2, 3. 2, 



2, 2, 4, 3, 1, IH. 2. 1. 2, 4. 1. 3. 2, 1. 1. 11, 2, 6H, •'>. 2. 50, 4, 2, 2, 3, 10. 2, 3, 3, 8, 1 'o 



Scab: 5, 7, 5, 1, 3, 2, 2, 2, 5. 2, 4, 3. 12, 3, 9. 1, 2, 2, 20. 10, 5, 11. 4. 10. 4. 7. 5, 9, 30. 



11. 2, 9, 2, 3, 5. 50 % 

 Hollow Rot: 12. 13, 3, 15, 10, 7, 6. 70, 9, 7, 18, 6, 4, 5, 7H, 6, 5, 2, 9, 15, 4, 1. 1, 8, 1, 3, 



3. 3"^. 



Second Growth: 16, 26, 45, 15%. 



Frost Injury: 10, 9, 7, 4, 1, 20, 40, 7, 3, 3, 14, 12 %. 



Cuts: 20, 2, 9, 5, 8, 7. 10, 13, 3, 12, 11, 15, 11, 9, 5, 6, 3, 4, 5, 15, 8. 6. 35, 8, 6, 7, 10,5. 

 11, 8, 6, 12, 10, 8. 5. 14, 14. 20, 15, 6 %. 



Total cars examined=200. 



A consideration of this table sliows that blacli heart may occur in rather 

 high percentage occasionally. Michigan cars frequently travel luuler heated 

 service and black heart may very likely be of more imix)rtance than the 

 figures show. 



The slimy soft rot of potatoes, C(»mmonly assigned to Bacillus carotovorous, 

 probably is not a clearly defined group. While the true soft rot organism can 

 rot potatoes weakly, it is of comparatively rare occurrence according to the 

 writer's observation. Many other organisms that commonly are found uix)n 

 tlie potato in nature cause soft rotting when potatoes are put imder luimM 

 conditions. 



Many forms of F\isarium decay under very luoist conditions simulafc 

 bacterial decay, Tlie breakdown following frost injury similarly may be con- 

 fused with a true disease inaugurated by bacteria. 



The loss by Fusarium rot is the most striking thing in the table, J);> of 

 tlie 2(K) <'ars reiMirted showed more or less loss from this source. The potatoes 

 that rot in this way are the mishandled, bruised, or cut potatoes, whose broken 

 .skins admit the decay organisms. The loss caused in this way is a commentary 

 npon the careless ban<lling methods in vogue in marketing potato tubers. 



Potato scab was frecpiently found in appreciable amounts, although all 

 potatoes inspected were of the TJ. S. Government No. 1 grade, and presumably 

 liad undergone some !«orting. 36 of the 200 cars showed loss from this source. 



Many tubers showed hollow heart and this cleavage of the flesh, usually 

 confined to the large potatoes, was a serious disadvantage in selling the crop. 

 The second growth potatoes and the frost injury are intimately connected 

 with points made concerning Fusarium rot and the means of combatting it. 

 The rather high percentage of cuts and bruises is important since these pota- 

 toes are the ones which are sure at some time to develop Fusarium attack. 



