April, ’23] 
smith: spreaders and spraying 
201 
casein in all applications. Nicotine Sulphate 40% (Black Leaf 40) 
was used at the 1 to 800 dilution and casein (Kayso) at the recommended 
rate of 1 pounds to 200 gallons of the spray solution. 
The spray outfit used was a 200 gallon Friend, equipped with two 
single-nozzle guns; the pressure maintained was slightly less than 200 
pounds. The materials were mixed, and the applications made, by 
Chilcott Brothers. 
When the peaches were picked, they were graded and results tabu¬ 
lated by varieties. As in the case of the apples, the variety variations 
were so slight that the results have been combined by plots in Table 2. 
Table 2.— Results of Tests with Casein Spreader on Peaches, Virginia, 1922 
Plot 1 
57,698 
Peaches 
Plot 2 
49,753 
Peaches 
Plot 3 
47,634 
Peaches 
Plot 4 
97,821 
Peaches 
Type 
Of Injury 
Regular 
Treatment 
No Spreader 
Regular 
Treatment With 
Casein Spreader 
Regular 
Treatment With 
Nicotine Sulphate 
40% 
Regular 
T reatment 
With Nicotine 
Sulphate 40% and 
Casein Spreader 
No. 
% 
No. 
% 
No. 
% 
No. 
% 
Curculio. 
2680 
4.64 
1927 
3.87 
2874 
6.03 
4143 
4.23 
Brown Rot. 
189 
.32 
87 
.17 
91 
.19 
795 
.81 
Scab. 
16 
.03 
15 
.03 
60 
.12 
70 
.07 
Sprav Burn. 
Plot Averages. 
192 
.33 
1.33 
69 
.14 
1.05 
309 
.64 
1.75 
185 
.18 
1.32 
The results on peaches in Table 2 parallel the results on apples in 
Table 1. Here again, the spray without a spreader gave equally as 
efficient protection to the fruit as the spray with a spreader added. 
President J. G. Sanders: The next paper is by Mr. R. H. Smith. 
SPREADERS IN RELATION TO THEORY AND PRACTICE IN 
SPRAYING 1 
By Ralph H. Smith, San Francisco , California 
Abstract 
Fog spraying works out poorly. Much can be said for high power spraying. 
Spreaders give a uniform covering with low pressures. Substances with very low 
surface tensions, such as saponin and soaps give too thin coatings, caseinate a thicker 
film deposit without affecting compatiblity. Wind and rain doubtless affect efficien¬ 
cy. A suitable spreader, such as calcium caseinate, increases efficiency, as shown 
by tests with the codling moth, Carpocapsa pomonella , green apple aphis, Aphis pomi 
and woolly apple aphis, Eriosoma lanigera. 
The tendency of sprays to collect in drops on smooth surfaces and the 
action of rain and wind in removing spray materials after they have 
Contribution from the Research Laboratories of California Central Creameries. 
