Abiotic disorders, invertebrates, pathogens, and vertebrates
can injure avocado fruit. Many disorders or pests can produce
more than one damage symptom.
Names link to more information on identification, management
or biology.
Click on photos to enlarge
| Scarred, scabby, or brown fruit
skins |
Avocado thrips
Identification tip: Brownish scars, often in a webbed pattern. Feeding from high-populations
of avocado thrips.
|
Mechanical injury
Identification tip: Brownish scars
from rubbing, symptoms that on the right fruit are called carapace
spot. Carapace spot resembles damage from scab fungus (Sphaceloma
perseae)
that occurs elsewhere, but scab disease is not reported in
California. |
Mechanical injury
Identification tip: Brownish scars from wind and twig abrasion. |
Avocado thrips
Identification tip: Slight
scarring, or light brown streaks on fruit near the stem.
Feeding damage by a low population of avocado thrips.
|
Omnivorous looper
Identification tip: Scattered brown scars and shallow
oval gouges from caterpillar feeding on fruit skins.
|
Mechanical injury
Identification tip: Brown scars including mechanical injury to a fruit that is pale yellow (left) from a lack of light because it grew in dense leaf litter.
|
| Specked, spotted, fouled, or discolored
skins—Top of page |
Latania scale
Identification tip: Grayish armored scale covers encrusting
fruit surface. |
Anthracnose
Identification tip: Black lesion spots and specks
on fruit that can appear while fruit are on the tree or not
until later after harvest. |
Sunburn
Identification tip: The exposed side
of sunburned fruit initially develops pale yellowish discoloration,
which later can darken in the center. |
Greenhouse thrips
Identification tip: Brownish or pale discoloration
on the skin. Fruit may be covered with black specks of greenhouse
thrips excrement. |
Persea mite
Identification tip: Necrotic spots in fruit skin,
uncommon damage by persea mites that usually feed only on
leaves and commonly cause foliage spotting and premature
leaf drop. |
Sooty mold
Identification tip: Blackish fungal growth on surfaces
contaminated with honeydew excreted by mealybugs, soft scales,
or whiteflies. |
| Black
or discolored large blotches on skin or decayed fruit—Top
of page |
Wildland fire
Identification tip: Large circular necrotic blotch, usually on
the bottom end of fruit. Resembles damage from fruit rots
and sunburn. |
Sunburn
Identification tip: Discolored circular
blotch from heat damage to exposed fruit, often beginning
near top of fruit. |
Fruit rot
Identification tip: Shriveled dry or soft and decayed fruit. Skin may be covered with patches of brown to purplish spores from fungi that also commonly cause trunk cankers and limb dieback. |
Phytophthora fruit rot
Identification tip: Black soft fungal decay, often
in a roundish blotch, frequently near the bottom of fruit.
Usually develops only after harvest, and then rots fruit
flesh. |
Stem end rot
Identification tip: Fruit decay or
dark rot that develops after harvest due to infection by
various various fungi, including those causing anthracnose and fruit and stem-end rot. |
Crick-side
Identification tip: Black or necrotic indentations in fruit. In
coastal growing areas occurs after weather suddenly changes
from cool to hot. |
| Chewed or gouged fruit—Top
of page |
Caterpillars
Identification tip: Brown to blackish, circular to irregular indentations or streaks chewed in fruit by amorbia (western avocado leafroller), omnivorous looper, or orange tortrix
|
Omnivorous
looper
Identification tip: Gouged
fruit skins from caterpillar chewing, often forming brownish
pits. Nearby leaves also are usually chewed.
|
Sunblotch
Identification tip: Indented or discolored streaks in skins from a complex of viroids. Sunblotch can also deform fruit and streaks on green branches, have a willowy canopy and/or alligator bark. |
Coyote
or dog
Identification tip: Distinctive
triangular canine tooth marks chewed in fruit.
|
Roof rat
Identification tip: Deep chewing on a ripe, fallen avocado fruit (left) and shallow chewing on a green fruit picked from a tree. Opossums, raccoons, tree squirrels, and certain other vertebrates cause similar damage. |
Mechanical injury
Identification tip: Chain saw pruning caused brownish gouges on fruit. |
| Abnormally shaped or distorted
fruit |
Cuke
Identification tip: Abnormally elongate fruit lacking a seed pit. A genetic mutation called ‘cuke’ because fruit resemble cucumbers. It’s more common on varieties like Fuerte.
|
Off-season fruiting
Identification tip: Abnormally round fruit, which can also
be caused by zinc deficiency. The dark patches are leaf
shadows.
|
Embossment or sectional chimera
Identification tip: A raised, dark ridge in
fruit skin caused by genetic mutation.
|
| 
Sunblotch
Identification tip: Deformed,
streaked, or discolored fruit from pathogenic viroids.
|
Crick or crick-side
Identification tip: A depressed, often black, indentation
on the stem end of avocado fruit. Cause unknown, possibly
due to high temperatures or water stress.
|
Woody avocado
Identification tip: A hard brown, gnarled structure superficially
resembling an avocado fruit. The cause is unknown.
|
