Viral diseases of banana

PAT 401

1. COLLEGE OF AGRICULTURAL TECHNOLOGY ( Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 VIRAL DISEASES OF BANANA Course teacher: Name: Dr.Parthasarathy.S , Chanchal Gireesh S Asst.,Professor ,(Plant Pathology) 2015021023

2. Viral diseases of banana Banana bract mosaic virus Banana infectious chlorosis Banana streak virus

3. Bract Mosaic Virus Banana bract mosic virus ( BBrMV ,) - locally known as kokkan . Symptom develops in primarily transmitted through infected suckers

4. Transmission Primary infection: Infected Sucker Secondary infection: mealy bugs

5. Symptoms Yellow streaks on leaves. Splitting of the pseudo stem. Abnormal emergence of the bunch from the middle of the pseudo stem. Produce fewer fruits of smaller size. Dark reddish-brown mosaic symptoms, which are especially obvious in bracts. Spindle-shaped chlorotic streaks running parallel to the veins. Distinctive dark colored mosaic patterns, stripes or spindle-shaped streaks are visible.

6. Streaks on bracts

7. Pinkish streaks on pseudostem

8. Management Practices Transmission by mealy bugs. Requires early detection, and immediate eradication of infected plants. Effective control of the disease, similar to that of other viral diseases. virus-free propagating materials should be planted

9. Banana Streak Virus Banana streak virus (BSV) is an important disease of Musa and affecting the productivity of both bananas and plantains. Reported in nearly all countries where this crop is grown including Mauritius, India and many countries of the African continent.

10. Symptoms The most characteristic foliar symptoms of infection are chlorotic streaks, which become necrotic with time. The leaf lamina may also be narrower, thicker and become torn. Stunting of the plant, constriction of the bunch on emergence (choking), altered phyllotaxis (leaves arranged in a single vertical plane instead of the normal spiral pattern), and detachment and splitting of the outer leaf sheaths of the pseudo stem.

11. Symptom

12. Management Practices The eradication of infected plants. The use of BSV-free planting materials. BSV can be carried in in-vitro plantlets, as it is not eliminated by shoot-tip culture. Virus particles can only be detected in areas of leaf tissue with symptoms. Parts of leaves with pronounced symptoms should be used for serological indexing.

13.   Infection chlorosis mossiac disease: Erwinia carotovora   sub sp.    carovora Infectious chlorosis one of the most common diseases in banana. The diseases causes yellowish green patches and thickening of veins Leaf sheaths also pull away from the pseudostem easily. Since the disease is caused by virus, chemical control is of no use

14. Symptom The disease is characterized by the presence of typical mosaic-like or discontinuous linear streaking in bands extending from margin to midrib. Rolling of leaf margins, twisting and bunching of leaves at the crown and a rigid erectness in newly emerged leaves The presence of dead or drying suckers is noticed in advanced cases referred as heart rot resulting from rotting of heart leaf and central portion of pseudostem

15. Primarily infected banana plants develop severe mosaic symptoms in young growth showing broadly streaked chlorotic or yellowish green bands and patches or chlorotic mottling distributed in patches over the leaf lamina The leaves are narrower and smaller than normal and the infected plants are dwarf and lag behind in growth. Such plants do not produce bunches but as a virus reservoir

16. Symptoms Linear streaking Bunching of leaves Rotting of heart leaf

17. Pathogen and vector Cucumber mossaic virus Aphis gossypii

18. MANAGEMENT Cultural method The banana gardens should be kept free from weeds.Infected suckers should not be used for planting.Weeds in the nearby areas should be removed as the virus survives in them in off-season. Growing pumpkin, cucumber and other cucurbits between the rows of banana crop should be avoided Early detection by regular inspection of planting and eradication of diseased plants from the field as soon as they are noticed. Use of high input crop management system comprising of 10 kg farm yard manure at the time of planting and subsequently at an interval of 3 months. 1 kg neem cake, 200 gm nitrogen, 40 gm phosphorus, 200 gm potassium per plant, 4 weeding at 2 months interval up to 8 months stage .

19. Chemical method Spraying Methyl Demeton 0.03 per cent (0.3 ml/lit of water) at 3 to 4 weeks interval controls the vector and reduces the spread of the disease. Foliar spray of micronutrient (0.2% CuSo4(2ml/lit), 0.2% FeSo4(2ml/lit), 0.5% ZnSo4(5 ml/lit) and 0.1% H3Bo3(1 ml/lit of water) at 3,5 and 7th month after planting and spraying Glyphosate 2Kg per hectare to control weeds.Control of insect vector by spraying Phosphomidon at 1 ml per litre or methyl demeton at 2 ml per litre

20. References T.S Thind “Diseases of fruit and vegetables and their management”. Kalyani publishers (page no:52-60). Bose S.K and Gupta B.P “Importance pest and diseases of temperate fruits.