Fungal diseases of vegetables-Bhindi

1. Fungal diseases of vegetables-
Okra(Bhindi)
Vaishali S.Patil
Assosiate Professor, Department of Botany
Shri Shivaji College of Arts, Commerce & Science Akola

2. 1) Cercospora Leaf Spot caused by Cercospora
abelmoschi, C. malayensis, C. hibisci
Symptoms- Leaf spots brown, irregular or sooty
black, angular spots . The affected leaves roll, wilt
and fall. The leaf spots cause severe defoliation.
Control- remove and dispose of infected leaves,
fungicide, crop rotation, Control weeds, Plant only
high quality certified seed.

3. 2) Fusarium Wilt caused by Fusarium oxysporum f. sp. Vasinfectum
Symptoms- Plants show temporary wilting symptoms, which become
permanent and progressive, affecting more plants. The leaves of the
affected plants show yellowing, loose turgidity and show drooping
symptoms. Eventually, the plant dies. In older plants, leaves wilt
suddenly and vascular bundles in the collar region become yellow or
brown. The fungus invades the roots, colonizes the vascular system and
thereby restrict water translocation. Cutting the base of the stem reveals a
dark woody portion along with dark brown streak underside of bark.
Control-Use on certified, disease-free seed; plant varieties with higher
resistance to the disease , fumigating the soil.

4. 3)Powdery Mildew caused by : Erysiphe cichoracearum,
Sphaerotheca fuliginea, Oidium asteris-punicei
Symptoms-The disease affects mainly the older leaves, petioles and
stems of plants, premature foliage loss. Increased humidity can increase
the severity of the disease, and infection is enhanced during periods of
heavy dew. The disease symptoms appear as blotches of white powdery
coating are mainly on the lower surface of the leaves but may appear on
the upper leaf surface also. Young leaves are almost immune. A large part
of the leaf surface is covered by the talc-like powder composed of
spores. Infected leaves may roll upward and appear scorched. Heavily
infected leaves become yellow, then become dry and brown. Extensive
premature defoliation of the older leaves occurs if the disease is not
controlled.
Control-Use overhead irrigation (washes fungus from leaves and
reduces viability); plant crop as early as possible; applications of
appropriate fungicides.

5. 4. Damping Off caused by Pythium spp., Rhizoctonia spp.
Symptoms-Damping off disease may kill seedlings before or soon after
they emerge. If the decay of the seedlings starts at emergence they fall
over the ground and die which is referred to as “damp-off”. When
seedlings on emergence develop a lesion near the collar region, the tissue
beneath the lesion soaks water and becomes soft due to which the
seedlings topple down on the ground and collapse.
Control- starting seed in light, well-drained, well-prepared soil or sterile
mix , treating soil with steam, dry heat or a fumigant; avoiding
overcrowding, excessive shade, overwatering, too deep planting, and
overfertilizing; and sowing crack-free, healthy seed dusted
with fungicide seed protectant. An early outbreak can be controlled by
applying a fungicide solution.

6. 5. Root-Decaying Disease caused by Macrophomina
phaseolina
Symptoms- This disease results in the death of the young
seedlings. The affected plants show dark brown to black
discoloration from the base of stems. The severely infected
plants die and their roots turn dark brown which are badly
damaged. The infected seeds appear brown to black and show
die-back and root rot.
Control- fungicide

7. 6.Anthracnose caused by Colletotrichum or Gloeosporium
Symptoms- Sunken spots or lesions (blight) of various
colours in leaves, stems, fruits, or flowers, and some infections
form cankers on twigs and branches.
Control- Destroying diseased parts, using disease-free seed
and disease-resistant varieties, applying fungicides, and
controlling insects and mites that spread anthracnose fungi
from plant to plant.

8. 7.Botrytis rots caused by Botrytis cinerea
Symptoms- grayish colored soft, mushy spots on leaves,
stems, flowers and on produce. Spots may become covered
with a coating of gray fungus spores, especially if humidity is
high. Fruit or plants shrivel and rot and often develop black,
stone-like sclerotia — a compact mass of hardened fungal
filaments — under rotted parts.
Control- improve air circulation, keep the soil under plants
clean and rake up any fallen debris, fungicides

9. 8.Phoma canker caused by Phoma exigua
Water soaked lesion appear on fruits. Black spots with
irregular margin Black area – pycnidial formation. Completely
rotted, the pod’s typical greenish color turning brown and the
infected tissues fully covered with mycelia. Internally,
immature seeds and placenta infected. Diseased tissues were
light brown to black. Externally, mycelia tend to be fluffy and
lighter in color, forming a large number of dark sclerotia on
the fruit surface.
Control- selecting varieties resistant,fungicides

10. 9.Verticillium wilt caused by Verticillium sp.
Symptoms- The leaves wilt and curl, and turn yellow or red.
They eventually turn brown and drop off. Stems and
branches die back. It’s not unusual to see these symptoms
on one side of the plant while the other side appears
unaffected.
Control- Destroy small, easily replaced infected plants.
Fertilize on schedule, using a low-nitrogen, high-
phosphorus fertilizer. Prune off dead and dying branches.
Solarization,

11. 10.Charcoal rot caused by Macrophomina phaseolina
Symptoms-Discoloration of stem at soil line; cankers on stem
may spread upwards; leaves may wilt and drop from plant;
numerous small black sclerota (fungal fruiting bodies) develop
in affected tissues and can be used to diagnose the disease.
Control- Rotate crop to non-host to reduce build-up of
inoculum in the soil; avoid water stress to plants by irrigating
when required

12. 11.Southern blight caused by Sclerotium rolfsii
Symptoms-Sudden wilting of leaves; yellowing foliage; browning stem
above and below soil; browning branches; stem may be covered with
fan-like mycelial mat
Control-Remove infected plants; avoid overcrowding plants to promote
air circulation; rotate crops with less susceptible plants; plow crop debris
deep into soil; provide a barrier to infection by wrapping lower stems of
plant with aluminum foil covering below ground portion of stem and 2-3
in above soil line

13. 12.White mold caused by Sclerotinia sclerotum
Symptoms-Flowers covered in white, cottony fungal growth; small,
circular, dark green, water-soaked lesions on pods leaves and branches
which enlarge and become slimy; cottony white growth may be visible
on lesions during periods of high humidity; death of branches and/or
entire plant
Control-Rotate crops with non-hosts like cereals and corn; plant rows
parallel to direction of prevailing winds to prevent spread of disease from
secondary hosts nearby; avoid excessive nitrogen fertilizer; use a wide
row spacing

14. 13.Phyllosticta leaf spot caused by Phyllosticta sp.
Symptoms: Large circular or irregular shaped leaf spots with
tan centers. The infected tissue becomes very thin, and breaks
out or larger.
Control-Manage overhead irrigation with minimal chances of
continued long periods of leaf wetness.

15. 14.Okra Blossom Blight caused by Choanephora cucurbitarium,
Symptoms: White cottony mass that develops black whiskers. These are
the pin-like fruiting structures of the fungus. The fungus grows on the
flower petals.
Control- Mulch beneath plants to create a barrier between the soil and
the plants’ foliage. Prune back plants in late summer to push out new
growth. After the plants begin blooming, use soaker hoses instead of
sprinklers to water thirsty plants. Harvest pods that grew from infected
blossoms while they are small. Clear away nearby vegetation that may
slow the drying of okra foliage and blossoms