New York Agricultural Experiment Station. 311 
Manured. 
Irrigated. . . 
Unirrigated. 
Practically there was no difference in the percentage of scabby 
tubers between the irrigated and unirrigated portion that was not 
manured. In the manured portion the number of scabby tubers was 
41 per cent greater in the irrigated than in the unirrigated. 
The Kelation Between Color of Skin and the Liability to Scab. 
To determine if any relation existed between the color of the skin of 
the potato tubers and the liability to scab, the yields of eleven 
hills each of forty-five different varieties tested in the garden were 
examined and counted with the following result: 
It appears that the dark-skinned varieties gave a smaller percentage 
of scabby tubers than the white varieties. Those having a flesh- 
colored skin appear to be most susceptible to the scab, the percentage 
of scabby tubers being greater than in either the white or dark-skinned 
varieties. Taking the average percentage of the scabby tubers 
produced by all the light-skinned varieties examined, forty-eight per 
cent were scabby. In this case the dark-skinned varieties were the 
least susceptible to scab. 
Whole No. Per cent, 
of tubers, scabby. 
Dark-skinned varieties . 
White-skinned varieties 
Flesh-colored varieties . 
531 27 
1,076 43 
529 53 
