Banana Bunchy top disease

Banana Bunchy top disease

1. COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 Banana bunchy top Student Course teacher B. Saran Kumar Dr.Parthasarathy.S 2015021022 Assistant Professor (Plant Pathology)

2. Name of disease Common names : Banana bunchy top. Other names : Bunchy top or Curly top or cabbage top or strangles disease.

3. Banana bunchy top Bunchy top virus or Banana virus – 1 or Musa virus-1 First reported from Fiji in 1889 in Cavendish varieties Around 1940, introduced into India from Srilanka through cyclone. Banana bunchy top virus is a ss DNA virus with single isometric particles.

4. Banana bunchy top virus (BBTV) Virus classification Group : Group II ( ssDNA ) Family : Nanoviridae Genus : Babuvirus Species : Banana bunchy top virus

5. Occurrence World : Asia, Africa, Australia and South Pacific areas. India : Tamil Nadu , Kerala, Karnataka and Andhra pradesh. Inventor : Fiji (1889). Hosts: Banana.

6. Economic Importance Banana bunchy top disease is the most serious virus disease of banana world wide. Diseased plants rarely produce fruit and when they do, the fruit is stunted and twisted. it is edible. The banana bunchy top disease has had a huge impact on the banana industry in Hawaii and Australia and among other areas of the world.

7. The disease was first seen on the Hawaiian island of Oahu in 1989 and by 2002, only 13 years later, it was a major disease on four of the Hawaiian islands (Hawaii, Oahu, Kauai and Maui). The movement of BBTV was mostly facilitated by human movement of diseased plant material and banana aphids from island to island. In the 1920s it almost completely destroyed the banana growing industry in Australia .

8. Symptoms Prominent dark green streaks on the petioles and midrib along the leaf veins. Green streaks range from a series of dark green dots to a continuous dark green line ( Morse code). Marginal chlorosis and curling of leaves. Petioles fail to elongate. Leaves are reduced in size, chlorotic , stand upright and become brittle and are crowded at the top (Bunchy top) and shoe dark green streaks with ‘J hook’ shape near the midrib.

9. Banana plant affected by bunchy top virus

10. Dark brown patches ©http://agritech.tnau.ac.in/crop_protection/banana_diseases/crop_prot_crop%20diseases_fruits_banana_3.html

11. Narrow hook-like extensions ©http://agritech.tnau.ac.in/crop_protection/banana_diseases/crop_prot_crop%20diseases_fruits_banana_3.html

12. Dark green streaks on leaves. © http://www.planthealthaustralia.com.au/wpcontent/uploads/2013/03/Banana-bunchy-top-disease-FS.pdf

13. Dark green streaks and chlorosis on leaves ©http://www.planthealthaustralia.com.au/wpcontent/uploads/2013/03/Banana-bunchy-top-disease-FS.pdf

14. Visible symptoms of BBTV ©http://www.planthealthaustralia.com.au/wpcontent/uploads/2013/03/Banana-bunchy-top-disease-FS.pdf

15. TRANSMISSION OF BBTV BBTV can spread from one plantation to the next by means of infected planting material and between plants with the Banana aphid, Pentalonia nigronervosa ( Hemiptera : Aphididae ). The immature aphid stages are small, reddish-brown to almost black, oval shaped, and wingless.

16. Vector Banana aphid ( Pentalonia nigronervosa ) ©http://www.planthealthaustralia.com.au/wpcontent/uploads/2013/03/Banana-bunchy-top-disease-FS.pdf

17. P. nigronervosa aphid colony visible in leaf sheath ©http://www.planthealthaustralia.com.au/wpcontent/uploads/2013/03/Banana-bunchy-top-disease-FS.pdf

18. Identification of pathogen : The virus is an isometric particle measure 20nm in diameter. It is ssDNA virus belonging to Nanoviridae family and Babuvirus genus. The virus has multi component genome There are six circular single stranded genomes known to be established. The virus concentration is more present in phloem. It is transmitted by infected suckers and banana aphid

19. Banana bunchy top virus © ©https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/banana-bunchy-top-virus

20. Disease cycle Primary spread : Through infected plant suckers. S. I. By Banana aphid, Pentalonia nigronervosa Reservoir hosts: Cucumus sativus , C. melo , Catharanthus roseus , Gynura aurantiaca, Colocasia esculenta, Amomum subulatum and Elettaria cardamom.

21. Management Cultural method: Adaptation of strict quarantine measures. Use virus free planting materials. Remove and rouging of infected banana plants. Chop, dry and bury the infected plants. Maintain clean, weed free field for early detection of infested suckers. Avoid banana cultivation in sugarcane and cucurbitaceous areas as sugarcane mosaic virus or cucurbit mosaic virus can easily spread to banana.

22. Chemical method Vector control with systemic insecticides, viz ., Phosphomidon @ 1ml/ l or Methyl demeton @ 2 ml / l . Acetamiprid , Clothianidin , Dinotefuran , Imidacloprid , Thiacloprid @ 2ml/l. Eradication of all infected suckers by spraying with kerosene or by injecting herbicide, 2, 4-D.