THE POTATO DISEASE. 



181 



described, yet it was found to have a diminishing effect on the 

 amount of produce where the crop was not so far advanced. 



Experiment with Potatoes as regards the effects of Lime. — 

 Potato sets from good sized tubers, of Jersey blues, were planted 

 when cut, March 9, 1846, from six to eight inches deep. Lime 

 was profusely scattered in the trenches in which the sets were 

 placed ; and after they were covered in, more lime was put on 

 the surface, which was then chopped with a hoe. 



Another portion was planted similarly to the preceding in 

 every respect, but without lime. The number of sets and extent 

 of ground were in both cases equal. 



The produce, sound and unsound, was as follows : — 



lbs. oz. lbs. oz. 



Limed portion sound 200 7. Unsound 19 15 



Not limed „ 192 6 „ 22 13 



In favour of limed portion .81 214 



It appears from the above, that the sound produce from the 

 limed portion was about four per cent, greater than that from 

 the portion not limed ; whilst the relative proportion of unsound 

 was fifteen per cent, in favour of the liming. 



The ground not having been previously affected by the appli- 

 cation of lime, it was rendered more tender for the potato 

 runners than where it was not applied in the above experiment. 

 Lime, with reference to the disease, appears to have produced 

 some degree of modification ; but it is not a decidedly specific 

 remedy, for the premature decay of the stems was alike in the 

 limed and unlimed portions. 



Experiment with Diseased and Sound Potato sets. — All 

 other circumstances being the same, the produce from 



lbs. oz. lbs. oz. 



Diseased sets was .... sound 197 8. Unsound 20 10 

 Sound sets „ 195 5 „ 22 4 



2 3 1 10 



In selecting the tubers to be cut in sets for the above experi- 

 ment, none were employed as sound that were in the least disco- 

 loured either externally or internally ; and, on the contrary, the 

 most deeply diseased were employed, provided the eyes were not 

 destroyed, in the portions cut out for sets for the part of the 

 experiment contrasting with that in which only sound tubers 

 were used. Contrary to what might have been anticipated, the 

 resulting produce was rather in favour of the unsound sets. 

 The total produce differed little ; but the quantity diseased 

 was nearly eight per cent, less from diseased sets than from 

 sound. 



Observations respecting the Depth of Planting. — The mass of 



