October, ’24] 
HERBERT: SPRAY STIMULATION 
569 
usually give the same stimulation that one emulsified as a Miscible oil 
does. In fact, certain makes of Miscible oil will show this more than 
others. 
Balfour Guthrie & Company manufacture a full line of Miscible oils 
and under the leadership of their entomologist, Paul R. Jones, have 
made an exhaustive study of the proper types of oil and emulsifiers for 
the best stimulation and Scale kill, and yet retain a high safety factor. 
Probably no other concern has the knowledge of the manufacture and 
field use of oil sprays that this company has. One reason for this is 
that they have been manufacturing oil sprays for some twelve or thirteen 
years and Mr. Jones, and the writer as well, had a number of years 
experience previous to this while working for the United States Govern¬ 
ment. There are certain ingredients in their Miscible oils which are not 
found in any other brand, at least not in the same proportions. 
Conditions Necessary 
Certain conditions must exist in the orchard before this stimulation 
will take place. 
The amount of moisture in the soil is one of the most important 
factors, therefore, the spraying should not be done until several inches of 
rain have fallen within a few weeks previous to the application. There 
must be plenty of plant food available in the soil. 
Naturally, one can not expect to obtain a crop by spraying only. 
The grower must give the orchard proper pruning, irrigation and culti¬ 
vation together with the spraying for the best results. 
In the California coast counties the proper amount of moisture will 
generally be present by early December. However, in 1923 the work did 
not start until the latter part of December, due to lack of moisture. 
Therefore, the work should be done from early December to the last of 
January. Although the stimulation has taken place at various times 
from materials applied throughout February, still one can not count on 
its happening from so late an application. Often too late an applica¬ 
tion will retard blossoming. 
Effect of Stimulation 
The effect of the stimulation is to cause a vigorous early bloom, vary¬ 
ing from five to twenty days earlier than normal, according to the dosage, 
time, weather and condition of the orchard. 
Prune growers in the Santa Clara Valley have found that a full 
bloom appearing before March 20th insures one of a good crop; appear- 
