140 



EXPERIMENT STATION. 



[Jan. 



A fertilizer of the following composition was used, applied 

 in the indicated amounts per acre : — 



Pounds. 



Nitrate of soda, 400 



Superphosphate of lime, ...... 1,320 



Muriate of potash, 280 



Lime, 1,000 



In order to be certain that the production or reduction of the 

 mosaic disease was due to the excess of fertilizer which was 

 added in each case, a growing medium was taken which con- 

 tained little or no plant food. In this case pure anthracite or 

 hard coal ashes, which had been sifted through a one-fourth- 

 inch sand sieve, were used. 



Five wooden boxes of the same dimensions (45 by 45 by 30 

 centimeters) were filled to a depth of 25 centimeters with the 

 ashes; to this was added in each case the requisite amount of 

 the complete fertilizer calculated from the above formula. 

 Box 1 contained the complete fertilizer, and nothing else ; to 

 box 2 was added an excess of nitrates equal to that already in 

 the fertilizer ; to box 3 was added an excess of potash equal to 

 that already in the fertilizer ; to box 4 was added an excess of 

 phosphate equal to that already used ; and to box 5 was added 

 an exeess of lime equal to that already used, — so that the 

 boxes contained : — 



Table showing Contents of Each Box. 



Two tomatoes were planted in each box, one being pruned 

 and the other not. They were allowed to grow for one week, 

 however, before the first pruning, then one plant in each box 



