Seasonal development
and life cycle—Brown rot
The fungus that causes brown rot survives the winter in infected twigs, inside dead, blighted blossoms
that remain on the tree, or in dried, rotted fruit on the tree or on the ground. Spores produced on these
sites in spring are carried through the air by wind and splashing water to infect flowers of the new year's
crop.
Brown rot infection and disease development will take place over a wide temperature range and flowers
can be infected from the time buds open until petals fall. Fruit is most susceptible to infection by the
brown rot fungus when it is ripe. Most fruit rot develops during the month before harvest, although rot
occasionally may develop on green fruit in early summer. Almond hulls may be infected from the time they
split until they dry. | 
Brown
rot overwinters on twigs in cankers
Dead
blighted blossoms
|
