APPLE POWDERY MILDEW AND ITS CONTROL. 19 
THIRD APPLICATION. 
The third application should be made three weeks after the second, 
and the insecticide regularly employed at that time should be added 
to the spray mixture, as directed under “ General formula for the 
spray mixture,’ on page 17. 
FOURTH APPLICATION. 
The fourth application should be made three weeks after the third, 
and the insecticides commonly employed at that time should be added 
to the spray mixture, as directed under “ General formula for the 
spray mixture,” on page 17. 
SPRAYING METHODS. 
In the spraying schedule kere recommended it will be noted that 
the intervals between the applications are never greater than three 
weeks. In order to avoid any risk of causing sulphur injury in the 
form of fruit dropping it is very important that strict attention be 
given to the timing of the application, and, if necessary, the intervals 
should be made less rather than greater than three weeks. Obvi- 
ously the weak dosage of iron-sulphid mixture recommended will not 
bring as marked and rapid mildew control as a stronger one would ; 
but if the spraying is consistently and regularly done good results 
will surely be obtained, and it has been a noticeable fact that when a 
portion of an orchard is given this treatment for one year that por- 
tion, as compared with the remainder of the orchard, has shown de- 
cided improvement when the trees leaf out the following spring. 
Such an effect is probably partly physiologic and partly the result of 
mildew control, and its bearing on the general condition of the trees 
is evident. 
Too much can not be said regarding the value and importance of 
thoroughness in spraying. <A very large proportion of the men who 
handle the spray rods have, to say the least, a very inadequate con- 
ception of a satisfactory job of spraying, and when it is remembered 
that every leaf is susceptible of mildew attack, the importance of 
taking time to do a thorough job should be apparent. 
Equipment is an important factor in good work. While prac- 
tically all the spraying in the Pajaro Valley is done with power 
outfits it is entirely out of the question to spray a hundred-acre 
orchard with a single machine and finish the work in anything like 
schedule time. Attention has been called to the great number of 
twig infections in the upper parts of the trees, which means that 
care should be taken to spray the tops thoroughly. Spray rigs hav- 
ing towers are not used in the Pajaro Valley, and it has been neces- 
sary to depend upon long spray rods for reaching the tops of old 
