12 



JOUBNAL OF AGEICULTURE OF P. E. 



With the exception of the kerosene emulsion, tliere was apparently 

 very little difference in the repellent properties of those chemicals. 

 None of them can be considered as first-class repellents. An experi- 

 ment with the same chemicals to test their killing ])owers gave such 

 conflicting results that it has not heen included in this report. 



The following experiment was carried out to test the value of 

 aome of the fertilizers previously referred to. when used under field 

 conditions. Plots of one hundred stools of cane were used tor each 

 different fertilizer, and at the end of the season the effect on the 

 yield and quality of the cane, and the number of white grubs was 

 <letermined. 



Experiment XV. — Manurial Agents as Deterrents for White Givib. 



From the data presented in the preceding table it is seen that of 

 the materials used cyanamid alone maintained its repellent effect 

 throiigliout the season. Its effect upon the yield, however, was not 

 good, and the cost of such a treatment, without obtaining a fertiliz- 

 ing compensation to partly offset tliis cost would make such a prac- 

 tice i)rohibitive. Further experiments with cyanamid alone have 

 moreover given but poor results and have failed to confirm the re- 

 sults previously obtained. 



The nitratt' of soda had an cxceUeiit effect on tlie yield and ap- 

 ))arently had some slight deterrent power. 



Hotli applications of kainit gave an increase in yield over the 

 check plot and exercised some (h'terreiit effect over tlie whit" grubs. 

 None of the fertilizers, however, can be considcired as giving results 

 of any very pfactical value in controlling the white grubs. 



•Mr. R. H. y<\\] Zwaluwenburg, entomologist of the Federal Ex- 

 periment Station, has recently (-arried out a series of four experi- 

 ments with cyanamid and with cyanamid and acnd phosphate, as 

 agents for killing white grubs (Plujllopliaga spp.) in cane lands. 

 His results are api)ended herewith. 



