Florida Agricultural Experiment Station


punctured by pressure of the finger. The initial stages of these
mold decays are often known on the markets as "pinhole" decay.
This soft spot enlarges rapidly and a white growth of mold
quickly develops on the surface. This is followed by the develop-
ment of olive-green, powdery spore-masses in the case of the
green mold, or by blue-green spore-masses in the case of the
blue mold (Fig. 52). The entire fruit is soon involved and finally
becomes a soft, rotten mass covered with a layer of olive-green
or blue-green spores, which rise up in a cloud when the fruit
is jarred. If the humidity is low or moderate the decaying fruit
may gradually shrink to wrinkled, dry mummies, but if the
humidity is high, other molds and bacteria may start to grow
and the fruit frequently becomes a settled, decomposing, soft
mass.
 Frequently, both molds are associated and it is common to
find the more generally occurring green mold developing after
the blue one has initiated the break-down of the fruit. When
both are present on the same fruit, the green color tends to be-
come predominant. The blue mold appears to break down the
inner tissues more completely than the green mold and usually
develops spore-masses inside the fruit as well as on the sur-
face.
 CAUSE OF MOLD DECAYS
 The blue and green mold decays of citrus are caused respective-
ly by Penicillium italicum Wehmer and P. digitatum Sacc. Most
of the so-called blue mold decay is in reality caused by the green
mold fungus. An injury to the protecting rind of the fruit is
necessary before the green mold fungus can attack it. The blue
mold, like the more common green one, attacks the fruit for
the most part through injuries to the rind but also has the ability
to pass from an infected fruit to a sound one in contact with it
(Fig. 53). For this reason, it is considered more serious than
the common green mold and has been designated by Fawcett as
the "blue-contact" mold. This mold may also enter the cut stem
or button of fruit injured by frost or that which has been held
for a long time in cold storage and break down the fruit as a
stem-end rot. Age and weakness of the fruit, atmospheric
humidity, and high temperatures are also contributing factors
for the development of both these mold-producing fungi.
 The injuries of the fruit which allow the spores of these mold
fungi to start decay are many and varied but are mainly due