105 



By fall of that year, the scale had so increased that but little fruit 

 in the orchard was salable, and in the spring of 1923, the orchard was 

 so badly infested by scale that no further attempt was made to save 

 the trees by spraying. On May 4 of that year, however, the only 

 trees of the orchard which were blooming, and practically the only 

 trees alive, were those which had been given the oil sprays the previous 

 spring. These blocks of trees were in a fairly vigorous condition, while 

 practically all of the lime-sulfur sprayed trees around them were dead. 

 The entire orchard was cut down during the next year because nearly 

 all the trees had been killed by San Jose scale. ( See Fig. 1 and 2.) 



Figure 1 



Outer rows of tree.s on separate plots, Olney, 111.. May 4, 1923. Row 



on the left had been sprayed with oil emulsion; row on the 



right, with lime sulfur. Lime-sulfur-sprayed trees all 



killed hy San Jose scale 



Experiments in University Orchard, Olney, Illinois, 

 Winter of 1922-23 

 The objects of the investigation in the winter of 1922-23 were as 

 follows : 



1. To determine the best formula for making a stock oil-emulsion. 



2. To determine the possibility of combining the oil emulsions 

 with other spray materials. 



3. To determine the efficiency of homemade oil-emulsions and com- 

 mercial oil-emulsions. 



