Fungal diseases of vegetables bhindi

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. 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- S unken spots or lesions (blight) of various colours in leaves, stems, fruits, or flowers, and some infections form cankers on twigs and branches. Control- D estroying 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- D estroy 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:  W hite 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