10 DEPARTMENT CIRCULAR 409, U. S. DEPT. OF AGRICULTURE 
enough to warrant a summary of the results obtained but not to 
justify further extensive tests. 
In 1921 and 1922, tests were made of 1-1-50 Bordeaux-oil, using 
1, 2, and 3 applications during the period for best rot control. One 
application of this spray was about half as effective, when all rots 
are considered, as 1 application of 3-3-50 Bordeaux-oil made at the 
same time. Two applications were slightly better than 1 application 
of the full-strength spray, but not so good as 2 applications of the 
latter. Three applications were about on a par with the same number 
of applications of the 3-38-50 Bordeaux-oil. 
A 2-2-50 Bordeaux-oil was used in 1, 2, and 3 applications during 
1922, with results about the same as for equal numbers of applications 
of 3-38-50 Bordeaux-oil. However, this reduction in the strength of 
spray below the standard 3-38-50 formula showed a distinct falling 
off in effectiveness in the case of melanose. 
Tests were made in 1922 with neutral Bordeaux-oil in which just 
enough milk of lime was used to combine with the standard quantity 
of bluestone, and also with “improperly prepared ” Bordeaux-oil in 
which concentrated stock solutions of bluestone and of lime were 
mixed before diluting. ‘The first in 1, 2, and 3 applications was fully 
as good as the standard Bordeaux-oil. The second was distinctly 
less effective than the standard mixture in 2 and 3 applications. No 
test was made with single applications. 
A copper soap spray containing one-half pound of copper sul- 
phate and 3 pounds of resin-fish oil soap in 50 gallons of water was 
used during 1921 and 1922 in tests with 2 and 3 applications, and 
during 1921 in a 1-application test. It was shghtly less effective 
than 3-38-50 Bordeaux-oil. 
In 1925 two tests with two applications of 80-20 lime-copper sul- 
phate dust were made on trees wet with dew. Instead of showing a 
gain in effectiveness the treated fruit developed about 10 per cent 
more rot than the untreated checks. 
LIME-SULPHUR SPRAYS 
During the four seasons of 1921, 1922, 1923, and 1925, lhme-sulphur 
solution was tested in 1-40 dilution and in three-application schedules 
during the rot-control period, April 15 to May 5. The results are 
shown in Table 2. 
During one of the four seasons in question no 3-application test 
of standard Bordeaux-oil was made; the two 2-application tests for 
that season have been included with the five 3-application tests for 
the other three seasons to furnish a basis for comparison. During 
these four years eight 1-application tests of standard Bordeaux-oil 
were made during the periods covered by the lime-sulphur schedules. 
The results of these are also included for comparison. 
Considering all rots, three applications of 140 lime-sulphur solu- 
tion were about one-fourth as effective as a single application of 
standard Bordeaux-oil spray and about one-fifth as effective as three 
applications of the latter. The effectiveness against the Phomopsis 
type of stem-end rot is in general about half as great as for the 
standard Bordeaux-oil. A surprising feature is that the Diplodia 
