120 
FLORIDA STATE HORTICULTURAL SOCIETY 
the flies and scale in check, giving the 
friendly fungi a chance to gain the ascend¬ 
ancy. It is probable that lime-sulphur, 32 
degrees Baume, of strength 1 to 50 or 75, 
would be a good spray to follow the sec¬ 
ond application of the Bordeaux. This 
should be used from two to three weeks 
after the Bordeaux and will serve the dual 
purpose of killing both the purple scale 
and the rust mites. 
In conclusion, the essential points to 
bear in mind are: (1) that “ammoniated” 
fruit is one of the symptoms of the dis¬ 
ease known as dieback; (2) that this dis¬ 
ease is favored by certain feeding condi¬ 
tions in the soil; (3) that the disease is 
to be prevented by righting these condi¬ 
tions; and (4) that Bordeaux mixture 
used as a spray is a good preventive for 
the marking of the fruit. 
PERMANENT AND TEMPORARY DISCOLORATION OF 
CITRUS FRUITS 
John R. Springer 
Discolorations of fruit may be divided 
into two classes: those which are tempo¬ 
rary and may be removed by washing or 
rubbing, and those which are permanent. 
Discolorations which are removable are 
caused chiefly by the sooty mold and the 
purple scale. The sooty mold, a fungus 
which grows on the honey dew secreted 
by the larvae of the whitefly, blackens the 
fruit, and by its light-proof nature, re¬ 
sults in uneven coloring. The washing 
necessary for its removal often results in 
mechanical injuries to the fruit, and thence 
blue mold decay. 
The oil sprays and the friendly fungi 
control the whitefly, and no fly, no mold, 
is a safe inference. The scale tends to 
delay coloring .of the fruit, and it sticks 
so tight, the ordinary washing will not 
remove it. The same treatment for the 
whitefly applies to the scale. 
The permanent russeting is, however, 
more of a problem. First taking up the 
russeting done by the rust mite: This 
mite, so small that it is only discernible to 
the naked eye when found in large num¬ 
bers, causes great loss each year to the 
fruit growers of this State. The russeting 
resulting from the attacks of this mite not 
only make the fruit less attractive and 
therefore less salable, but the hardening 
of the skin caused by the extraction of the 
essential oil normally found in the rind, 
prevents complete growth and the result 
is smaller fruit. This alone often cuts 
from 20 to 25 per cent from the estimated 
crop. The grower should not wait until 
he sees his fruit covered with the mite be¬ 
fore he starts to spray, but using a popu¬ 
lar expression, “beat them to it.” In the 
spring the mite is found on the older 
growths. It migrates from here to the 
new wood, after it has hardened a little, 
and later on to the fruit. If the season is 
dry, special attention should be paid, as 
the mites develop rapidly in dry weather. 
If the mite is found in any considerable 
numbers early in the season, the first 
