FLORIDA STATE HORTICULTURAL SOCIETY 
ii 7 
been if the mites had not been present. 
This reduction in size is the cause of a 
large part of the monetary loss which 
the industry sustains from this pest. 
The opinion is held by many growers 
that the rust mite does not reduce the 
size, but this is certainly erroneous. Chase 
& Company have found out by actual 
tests many years ago that the increased 
size that the fruit attains by spraying for 
the control of this pest more than paid 
for the cost of spraying and the addi¬ 
tional price which sprayed or bright fruit 
obtained in an early market was clear 
gain. M.r. F. D. Waite is of the opinion 
that the rust mite reduces the crop in Flo¬ 
rida on an average of from i to 2 sizes. 
I have recently figured out the reduction 
in size caused by this mite in many car¬ 
loads of fruit and a few cars will be given 
as an illustration. This reduction is 
figured as follows : the total number of 
fruits and the average number per box 
of each grade was obtained, and the num¬ 
ber of fruits of the russet grade was di¬ 
vided by the average number of fruits 
per box of the bright grades. This would 
give the number of boxes of fruit there 
should have been if the russet fruit had 
been as large as the bright fruit. From 
data obtained in this way from 40 cars 
of fruit in every instance the grade in 
which the largest number of bright fruits 
were included averaged a smaller number 
per box than the other grades and the 
grade in which was included the fruit 
known as “golden” was larger than the 
fruit in the grade which was largely rus¬ 
set, this percentage ranging from 2 to 14. 
Not only does it require more fruits 
for a box of golden or a box of russet 
than it does a box of brights, but the per¬ 
centage of the desirable sizes is much 
greater in the brights than in the other 
grades. In every instance in these 40 
cars the percentage of the 150, 176 and 
200 sizes was considerably greater in the 
bright grade than in either the golden or 
the russet grades. The small sizes are 
in most instances in the goldea or russet 
grades. 
( 
In addition to the reduction in size 
which the rust mites cause it should also 
be carefully noted that this pest reduces 
the fruit one grade. If no rust mite were 
present, or if it were controlled by the 
sulphur sprays 85 to 90 per cent of the 
fruit would be known as brights or placed 
in the first grade. As it is, really very lit¬ 
tle fruit shipped goes under the first or 
fancy grade brands. 
It should be stated that these figures do 
not show as great a reduction in size as 
actually exists because little or none of 
the commercial grading has been done 
strictly according to brights and russets. 
All the large, coarse, fruit, as well as more 
or less fruit that is inferior, is-placed in 
the russet grade regardless of whether 
they are russet or bright. 
In one packing house an orange which 
did not show more than 50 per cent dis¬ 
coloration was placed in the second grade, 
or which might be known as “golden.” 
As a general proposition over 10 per cent 
discoloration places the fruit in the gol¬ 
den grade. It must also be borne in mind 
that little or none of this fruit is entirely 
free from rust mite injury which of 
