3 
distinct and valuable methods of control noted below. Later studies of 
the action of this wash in California led the writer, in 1900, to give it 
a further careful trial in the East, with most successful results, demon- 
strating that, with favoring conditions, i. e., absence of dashing rains 
for a few days subsequent to the application, it would give just as good 
results in the Eastern States as on the Pacific coast. A year later 
(1901-2) very elaborate tests conducted by Dr. Forbes in Illinois showed 
that fairly hard rains will not always invalidate spraying with this mix- 
ture. A vast amount of experience of the most practical kind since 
gained, contributed to by all the eastern experiment stations and by 
the big commercial fruit growers of the Middle and Eastern States, 
has fully demonstrated the practical merit of this wash and its supe- 
riority to others in point of safety to trees and in cheapness. The 
wash is furthermore a valuable fungicide and is notably useful against 
the peach leaf curl, sprayed trees being practically immune from this 
disease, so that the cost of treatment is often more than made good 
by the fungicidal benefit alone. Its disadvantages are the difficulty 
of preparation and the heavy wear which it entails on apparatus— 
objections, however, which do not offset its notable advantages, par- 
ticularly for commercial-orchard work or where the number of trees 
to be treated is sufficient to warrant the trouble of its preparation. 
It is, in fact, the standard spray now used in commercial orchards for 
the San Jose scale. 
In the matter of composition of the wash, scarcely any two experi- 
mentersagree. Salt was a part of the original composition of the sheep 
dip and has long been retained, with the idea that it added, perhaps, to 
the caustic qualities, and particularly to the adhesive nature of the wash. 
For the latter purpose a very small amount only, 1 or 2 pounds to the 
bushel of lime, need be added, following the custom in the prepara- 
tion of whitewash mixtures. In practical experience, however, the salt 
seems to have been of very little benefit and is therefore omitted in the 
formula now given. The proportion of lime and sulphur is a matter of 
some indifference. The mixture obtained 1s sulphide of lime, and if an 
excess of lime 1s used it simply remains undissolved in the mixture and 
adds to the whitewashing character of the application. Too much lime 
is distinctly objectionable, however, because of the greater difficulty of 
spraying and harder wear on the pump and nozzles. The formula here 
given is substantially the one which has been hitherto recommended by 
this Bureau, reduced to the 45 or 50 gallon basis, or the capacity of the 
ordinary kerosene barrel commonly used in its preparation by the steam 
method. 
lWinslalkediplitmemere es ft ey ee ee! & pounds. . 20 
TEL tHrnS| (007 SoU) 1 oe ea a eo dossss 15 
WHAteninOnnNaKenerte po Ae 2 of os wees ese els oes gallons.. 45 to 50 
The flowers of sulphur, although requiring somewhat longer cooking, 
seems to make a better wash than ground sulphur, but the latter may 
