BORDEAUX-OIL EMULSION. 19 
trees were free from scale insects and white flies when planted and 
since there was no favorable source for reinfestation, these pests did 
not become abundant on any of the plats or even on the check. 
GROWERS' EXPERIENCE. 
A number of commercial growers have obtained results from the 
use of Bordeaux-oil emulsion similar in many respects to those 
obtained in the experimental work herein reported. Accounts of 
these may be of assistance in determining the value of such a spray 
for use in commercial groves. 
This combination spray was used by a few growers during the 
spring and early summer of 1920 for the control of scab and melanose. 
The following year it was applied in Alabama and Florida by a 
much larger number of growers, and in 1922 it was rather generally 
employed in both of these States. Variable results were obtained, 
but in general the control of fruit diseases was directly proportional 
to the thoroughness and timeliness of applications and was as effec- 
tive as would be expected from plain Bordeaux mixture. 
Where oil sprays were subsequently applied at the proper time, 
scale insects did not increase markedly. In a good many instances, 
for one reason or another, the summer oil sprays were not applied, 
and in most of these groves scale insects became very numerous and 
did considerable damage. In rare instances groves not sprayed 
with oil during the summer were not injured by scale insects, owing 
largely to the almost total absence of this pest in the grove or to the 
fact that copper sprays had been applied several months before the 
season of activity of the entomogenous fungi. As a general rule, 
rust-mite russet was found to be more severe in groves sprayed with 
Bordeaux-oil emulsion than on unsprayed property, and this in- 
crease in the insect pests may reasonably be attributed to the almost 
complete temporary destruction of entomogenous fungi. 
To sum up, Bordeaux-oil emulsion has generally given the growers 
who used it very satisfactory results in all cases except where the 
impossible was expected or where negligence on the part of the grower 
permitted scale insects to become excessively numerous. 
SPRAY-BURN. 
Four distinct types of spray injury have been observed on trees 
sprayed with Bordeaux-oil emulsion. In 1920 some injury was 
observed on fruits which had been sprayed at weekly intervals from 
April until August. This blemish resembled somewhat the small 
raised pustules of ammoniation or, at first glance, might be confused 
with melanose spots. They were found for the most part in patterns 
somewhat resembling rust-mite russet. A second injury is a scorch- 
ing of the very tender leaves and twigs comparable in a measure with 
mechanical injury caused by holding the spray nozzle too close to the 
tender parts. This type of injury has been observed on only three 
properties, and in each instance the water was unusually hard. In 
the grove where this injury was most prevalent another source of 
water was used, and the injurious effects did not follow. Apparently 
the trouble was due to mineral salt in the hard water. 
• So-called star melanose, the third type of spray injury, was ob- 
served on orange leaves in 1921 and 1922, but not in sufficient quan- 
tity to be of more than passing interest. 
