August, '16] 



McCOLLOCH: DUSTING FOR CORN-EAR WORM 



397 



It has been suggested that some carrier, cheaper than sulphur, could 

 l)e used with the arsenate of lead. In order to gather data on this 

 point, two additional one-fifth acre plots adjoining the previous experi- 

 ment were dusted, using flour and lime as carriers. Table II gives the 

 lesults of this test. 



Tarle II 



From these results it will be seen that with the use of sulphur there 

 was a lower percentage of ears injured and the cost of the treatment 

 was considerably lower. Lime and flour did not seem to adhere to the 

 silks and consequently a larger amount of material was used. There 

 was considerable mold and fungous injury on plots 9 and 10 which 

 w'ould indicate that the sulphur plays an important part in the dust 

 spray as a fungicide. 



In order to confirm the statement in the previous paper that the 

 50 per cent arsenate of lead was not effective enough to warrant its 

 use, a plot was dusted with equal parts of arsenate of lead and sulphur. 

 The results of this experiment are shown in Table III. 



Tablk III 



