AND OTHER INJURIOUS INSECTS OF I907 AND I908. 



81 



dry Bordeaux and Paris green (General Formula XX), at the same 

 dates upon which the others were treated. The dust sprayed trees 

 further were given one extra treatment on August 13th. The total 

 count of the apples in the block treated with liquid Bordeaux gave 

 eighty-one per cent marketable and nineteen per cent unmarketable, 

 while the dust sprayed trees showed seventy per cent marketable as 



Fig. 31. Plum leaves sprayed with Bordeaux and arsenate of lead (3 lbs. to 50 

 gals.) after four weeks' exposure to weather. Chemical analysis gave trace of 

 arsenic. 



against thirty per cent unmarketable. In other words, there were 

 sixty-two per cent more marketable apples than unmarketable in the 

 liquid sprayed lot, and only forty per cent more marketable than un- 

 marketable in the dust sprayed. I'hese counts were all made on 

 Duchess trees. Another block of nine different trees sprayed as above 

 with dust, showed only forty-three per cent of marketable apples, 



