56 EXPEKIMENTS WITH REFERENCE TO THE POTATO DISEASE. 



In the meantime, the ground allotted was traced into square 

 yards. At equal distances from the centre of each of these 

 square yards of ground 2 whole potatoes were placed on the 

 surface, 8 inches apart. Alleys a foot wide were then marked 

 off in the direction of the lines by which the square yards were 

 traced, and j pint of the soapy gelatinous compound was poured 

 on the sets in each square. They were covei'ed with 3f inches 

 of soil; by taking it 3 inches deep from the alleys. In this 

 manner 90 hills were planted, each 2 feet square ; but with the 

 alleys the whole occupied 90 square yards. 



The results obtained from liills 1 to 30 inclusive are given 

 in Table II. In these hills tlie plants were not earthed up. 

 With the exception of weeding, nothing was done to them from 

 the time the tubers were planted and covered with between 3 

 and 4 inches of soil till the produce was taken up. In all tliese 

 hills the produce was more or less diseased, in proportions vary- 

 ing from little more than 1 per cent, to 53 per cent. The 

 average was about 21^ per cent. The greatest amount of sound 

 produce, estimated per acre, was 19 tons 3 cwt. 59 lbs., the 

 least 3 tons 4 cwt. 92 lbs. 



Table III. — Results of Experiments with Jersey Blue Potatoes, 

 planted whole, in hills, each hill occupying one square yard. Com- 

 position of potash, fat, common salt and water applied to the Sets ; 

 Plants once earthed up. 



Jersey Blue Potatoes, planted in hills and earthed up tvhen 

 8 inches high ; the application of the potash, fat, salt, and water 

 composition being the same as in the preceding experiment. The 

 results from these hills, 31 to 45, are given in Table III. There 

 it will be observed that the plants in 7 out of the 15 hills had 

 no diseased tubers, and that the average proportion diseased was 



