How Molds Affect Citrus Crops

Blue and green mold are two of the most importantand cooling fruits while they are being stored and
post-harvest diseases that can affect a citrus crop.shipped are a good way to decrease the amount of
The infection that occurs the most frequently is greeninfections in a shipment. Losses from these molds can
mold and it is caused by the mold Penicillium digitatum. Italso be greatly reduced by taking special care during
exists in all citrus fruit growing regions and is a seriousharvesting and transporting not to bruise or break the
threat to the citrus industry.skin of the fruits.
When the fruit is bruised or punctured while it is beingFruits mainly become infected when their outer skin is
harvested or packed, the mold enters the fruit throughbroken and mold spores make their way inside either
these wounds and therefore, this disease can befrom contaminated soil, another infected fruit, or
contracted by fruit on the tree, in the packinghousethrough the air. Fungicides can also be used to reduce
where the fruit is prepared for the market, while inthe amount of infections. Also, any equipment used to
transit to the store, in storage, and the retail store.pack the fruit and anywhere they are stored should be
At first, only a white mold is seen growing on thesanitized every day to reduce the chance of the fruit
outside of the fruit and later begins to turn green duebecoming infected.
to the large amount of spores that are being producedThe spores of both of these molds are very easily
on the surface of the fruit. The fruit begins to decayspread by air currents and any fruits that are
and become soft. It shrivels up and dies as a result.contaminated with them should not be exposed to
Blue mold is caused by the fungus Penicillium italicumwind or other currents of air near any healthy fruit due
and it is different from green mold mainly because ofto the likelihood of it becoming infected.
the color. The conditions that the two molds grow inFruits can also become infected due to other physical
are very similar and tend to grow best at around 75injuries such as those associated with stem-end rind
degrees Fahrenheit.breakdown and chilling injuries.
Their growth is slowed by lowering the temperature