130 Observations on the Habits o/Oscinella frit 



Synopsis VII. Manurial Treatment. 



Rate of manuring per acre in Vassiliev's experiments: 

 Soluble phosphorus 16 lbs. in the form of superphosphate. Potassium 

 55-8 lbs. Nitrogen 21-2 lbs. in the form of saltpetre. 

 Rate of manuring per acre in present experiment : 



Soluble phosphorus 37-6 lbs. in the form of basic slag. 

 Potassium 27-2 „ „ kainite. 



Nitrogen 23-0 „ „ sulphate of ammonia. 



The slag and kainite were worked into the ground on Feb. 25th 

 before sowing and sulphate of ammonia was applied as a top dressing 

 on April 22nd. 



Vassiliev's experiment. Present experiment. 



Percentage killed on unmanured plots 21-0 9-2 



The manurial value will only show in the increased yield and the 

 reduced percentage of plants killed. The results of the two experiments 

 are very similar, even though, except for nitrogen, the rates of manuring 

 are different. The percentage of plants attacked necessarily includes 

 plants with attacked tillers, and as these are liable to be infested through- 

 out the season, it is not surprising that this percentage is practically the 

 same on all the plots. 



Phosphorus and potassium alone have very little value. The nitrogen 

 plots confirm the accepted opinion that the stimulus of nitrogen tends 



^ The yield in this experiment was the rate per acre, the grain being reckoned in bushels 

 of 42 lbs. and the straw plus chaff in cwts., the figures being derived from the analysis of 

 the contents of circles 4 feet in diameter. I am indebted to Professor Somerville for the 

 provision of the necessary labour and materials for the conduction of this experiment and 

 also for the yield figures. 



