Pineapple diseases A Lecture on ToT By Allah Dad Khan

2. Pine apple Diseases
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan

3. Mealybug wilt
Pineapple wilt virus (PWV)Symptoms Pineapple plants infected
with mealybug wilt
 Leaves turning red; tips of leaves
become withered and turn brown;
plants can be easily removed from
the soil
 Cause
 Virus
 Comments
 Virus is transmitted by mealybugs;
ants protect mealybug populations
from predators and parasites and
can allow mealybugs populations
to reach very damaging levels if
left uncontrolled
 Management
 Ants should be controlled with an
appropriate insecticide

4. Bacterial heart rot and fruit collapse
Erwinia chrysanthemi
Symptoms
 Water-soaked lesions on the white basal
sections of leaves in the central whorl which
may spread to all leaves in the central whorl;
midportions of leaves become olive green in
color with a bloated appearance; infected fruits
exude juices and the shell becomes olive green;
cavities form within the fruit
 Cause
 Bacterium
 Comments
 Disease is thought to be spread from the juices
of infected fruits; bacteria in the juice can enter
leaves through wounds; ants acts as vectors for
the bacteria
 Management
 Remove and destroy infected fruits; avoid the
use of infected crowns for seed material to
prevent spread of the disease; planting to avoid
flowering when adjacent field is fruiting can
reduce disease development; use of miticides
and control of ants can significantly reduce
disease incidence

5. Marbling
Acetobacter spp.
Erwinia herbicola
Symptoms
 Yellow to red or very dark brown
discoloration of fruit flesh; infected
tissues develop a granular texture with
woody consistency and speckled color;
single or multiple fruitlets may be
affected; vascular system may appear
speckled right down to core of fruit;
symptoms develop during the last
month of fruit maturation
 Cause
 Bacteria
 Comments
 Emergence of the disease is favored by
warm, wet weather
 Management
 There are currently no methods of
controlling the disease; the pineapple
variety Smooth Cayenne appears to be
moderately resistant to the disease

6. Butt rot, Black rot & White leaf spot
Chalara paradoxa
Symptoms
 Soft black rot which begins at the area where the
seed piece detaches from the mother plant; entire
seed piece may be rotted; black rot of fruit causes a
soft, watery rot which darkens with time; small
brown, wet spots develop on leaves; leaf spots
enlarge and turn gray-brown with light brown
margins
 Cause
 Fungus
 Comments
 Fungus survives in soil and pineapple residue;
infects plants through fresh wounds
 Management
 Seed material should be stored on mother plants
during dry weather and with good air circulation;
freshly removed seed material should be dipped in
an appropriate fungicide within 12 hours of removal
from the mother plant; avoiding bruising and
wounding of fruit during harvest helps to reduce
black rot; harvested fruit should be dipped in an
appropriate fungicide within 6-12 hours of harvest
to prevent disease development during shipping

7. Phytophthora root rot
 Symptoms of Phytophthora root rot in
pineapple field

8. Phytophthora root rot
Phytophthora symptoms
on pineapple fruit
Phytophthora symptoms
on pineapple