Agriculture Reference
In-Depth Information
prevent the disease. Rainfall is important for the build-up
of the fungus in damaged leaf hairs, but not for infection.
Fusarium guttiforme
enters the fruit through open f flowers
or injury sites. The risk of disease caused by this fungus is
higher when f flowers are initiated and fruit mature under
warm conditions (21-27
Importance
Fruitlet core rot is widespread but sporadic. It is an internal
blemish not usually detected on the farm. The disease is
most common in fruit maturing during winter or spring.
Rough-leaf pineapple cultivars are more susceptible than
smooth-leaf varieties.
°
C).
FUSARIOSIS - BIOSECURITY THREAT
Cause
Considered a distinct strain of
Fusarium guttiforme
(formerly
F. moniliforme
).
Symptoms
Fusariosis affects all parts of the pineapple plant but is
most conspicuous and damaging on fruit. Fruit
symptoms include a light to dark brown discolouration
of fruitlets and exudation of gum. Infected
plants exhibit stem rosetting and curvature
of the plant because portions of the stem are girdled
or killed.
Fig 16.9 Close-up of gum exudate at the base of the fruit, a
symptom of fusariosis.
Source of infection and spread
Infections of the inf lorescence and fruit occur primarily
via injuries caused by insects, particularly the pineapple
fruit caterpillar (
Thecla basilides
)
.
Infected planting
Fig 16.8 External symptoms of fusariosis, showing brown
discolouration and gum exudate. Inset: symptoms in cut fruit.
Fig 16.10 Heart leaves are easily removed from plants affected by
fusariosis.
