Norman Cunliffe 131 



to limit the damage by decreasing the percentage of plants killed. The 

 percentage of grains damaged was unaffected (the grain in turn being 

 always subject to attack), but on the nitrogen plots the plants were more 

 forward and therefore produced grain and straw of slightly greater bulk. 



Although the general infestation was about equal in both experiments 

 the severity of the attack, in the present experiment, was evidently not 

 so great in the first instance, as the percentage of plants killed on the 

 unmanured plots was only 9 per cent, as against 21 per cent.^ It was 

 to be expected therefore that the percentage increase in yield would also 

 be somewhat less. The cost of application of these manures was not 

 covered by the increased yield. 



Advantage was taken of an experiment conducted by Professor 

 Somerviile last season to test the relative advantages of sulphate of 

 ammonia, nitrate of lime and nitrolim as nitrogen conveyers, if used for 

 limiting frit attack. The procedure of sampling (average of plants ex- 

 amined per plot, 393) and estimation of yield was as above, and from 

 the synopsis below it will be seen that although nitrate of lime was 

 slightly better than sulphate of ammonia, while nitrolim was much the 

 reverse, none of the three gave a high yield with a low percentage of 

 plants killed. It should be pointed out that sodium nitrate was not 

 available for either of these experiments. 



Synopsis VIII. Treatment with Nitrogenous Manures. 



"Excelsior" oats drilled in on 10.3.20, on plots adjacent to one 

 another. 



Plots manured 19-21. 4. 20. Rate of manuring per acre in terms of nitrogen: sulphate 

 of ammonia plot, 17-2 lbs.; nitrate of lime plot, 18-2 lbs.; nitrolim plot, 22-4 lbs. 



Percentage Percentage Percentage Yield per acre 



It is considered that the nitrogen, from the nitrate of lime, was as 

 readily available as it would have been if sodium nitrate had been apphed 

 as a top dressing, in place of nitrate of lime. The manures were applied 

 before the flies emerged in appreciable numbers, yet even this early 



^ The soil of the plots on which Vassiliev worked is recorded as being very deficient in 

 phosphorus and nitrogen, which probably accounts for the high percentage of plants killed 

 on his control plots and the high percentage increase in yield. 



