Brown rot is one of the most dangerous diseases that affect stone fruits like plums , cherries, apricots, pears, sour cherries.
This disease is caused by the fungi Monilia laxa and Monolinia fructicola and it damages shoots, branches and fruits.
How to spot it
In spring some blossoms will turn brown and die. It is very similar to frost damage but blossoms affected by frost damage fall as the ones affected by brown rot stay on the tree.
When frost damage hits it affects blossoms uniformly as with brown rot you will see affected blossoms here and there.
On branches, you will see the top of the branch curling and the leaves turn brown and do not fall off the tree.
On fruits, you will see brown spots that appear when the fruit is ripe and with time this fruits will become dry and wither.
How it spreads
The fungi overwinter on wither fruits and on infected branches and twigs.
In spring, the fungus starts growing but it needs wet conditions ( rain , high humidity) and produces spores. The spores are then spread to the blossom by wind and rain ( the flowers must stay wet for several hours for the infection to start).
As the infection spreads it goes from the blossom into the bark where canker can appear.
Infected fruits produce grayish spores that can easily be transferred to other fruits on the same tree or on fruits on a different tree.
Damage
This is a very dangerous disease as it affects multiple organs of the tree. Besides the flower loss in spring , which is devastating for the grower, an infection in the branches could lead to the death of the fruit tree.
Control
Like most fruit tree diseases, brown rot can be controlled just by maintaining a clean orchard or garden :
- you should start with gathering the infected fruits of the groung an from the tree and distroy them.
- prune the infected branches and get rid of them.( that means the branches with canker or the ones that were affected by brown rot)
- if that is not enough, you can use fungicides to combat brown rot
Garden and Orchard 