Diseases of banana

the write down slide preparation of major disease of banana as like fusarium wilt, moko disease and bunchy top of virus etc

1. Diseases of Banana Khushboo Dubey Dept of Plant Pathology TMU, Moradabad

2. Panama disease/wilt

3. Fusarium oxysporum f. spcubense Yellowing of the lower most leaves starting from margin to midrib of the leaves. Yellowing extends upwards and finally heart leaf alone remains green for some time and it is also affected. The leaves break near the base and hang down around pseudostem . Longitudinal splitting of pseudostem . Discolouration of vascular vessels as red or brown streaks. The fungus spreads through use of infected rhizomes Continuous cultivation results in build up of inoculum .

4. Pathogen Mycelium is septate , hyaline and branched. Fungus produces micro, macro conidia and also chlamydospores . Micro conidia - Single celled or rarely one septate hyaline elliptical or oval . Macro conidia - Sickle shaped hyaline, 3-5 septate and tapering at both ends. Chalamydospores - Thick walled, spherical to oval, hyaline to slightly yellowish in colour.

5. Mode of spread and survival The pathogen is soil borne. It survives in soil as chlamydospores for longer periods. The primary spread of the disease is through infected rhizomes and secondary spread is through irrigation water.

6. Management Avoid growing of susceptible cultivars viz., Rasthali , Monthan , Red banana and Virupakshi . Grow resistant cultivar Poovan . Corm injection of 3 ml of 2% Carbendezim injected in the corm by making a hole to a depth of 10cm with 45 angle on 5 and 7 month a smentioned earlier . Soil drench with 0.1% carbendazim or 0.01% Vapam

7. Moko disease / Bacterial wilt

8. Pseudomonas solanacearum / Ralstonia / Burkholderia solanacearum Leaves become yellow and progress upwards. The petiole breaks and leaves hang. When it is cut open discolouration in vascular region with pale yellow to dark brown colour. Thediscolouration is in the central portion of the corm. Internal rot of fruits with dark brown discoloration . When the pseudostem is cut transversely bacterial ooze can be seen

9. Pathogen / Disease cycle Moko disease is caused by race 2 of Ralstonia solanacearum which infects Musa and Heliconia . Cells of bacterium are rod shaped and motile by 1-4 flagella. They are Gram negative P.I: Through diseased plant suckers used for planting. ➢ S.I: Through irrigation water, implements and by insects.

10. Management Grow resistant varieties like poovan and monthan . ➢ Adopt strict plant quarantine and phytosanitary measures ➢ Use of healthy planting material. ➢ Disinfestation of tools with formaldehyde diluted with water in 1:3 ratio. ➢ Crop rotation (3 years rotation with sugarcane or rice) & providing good drainage ➢ Allow fallow period or flooding during off-season ➢ Fumigation of infected site with Methyl Bromide or chloropicrin. ➢ Spray systemic insecticide to prevent transmission of disease to healthy plants. ➢ Biocontrol with Pseudomonas fluorescens

11. Bunchy top / Curly top / cabbage top /strangle disease

12. Bunchy top virus or Banana virus - 1 or Musa virus - 1 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. ➢ Flowers display mottled and streaked discolouration ➢ Plants show marked stunting

13. Pathogen/Disease cycle The virus belong to genus nanovirus and family Nanoviridae . The virus is isometric and ssDNA with multipartite. P. I. Through infected plant suckers. S. I. By Banana aphid, Pentalonia nigronervosa

14. Management Eradication of all infected suckers by spraying with kerosene or by injecting herbicide, 2, 4-D ➢ Use of only certified banana suckers for planting The new crop should be regularly inspected and the diseased plants destroyed as soon as noticed. ➢ Vector control with systemic insecticides, Viz., Phosphomidon @ 1ml/ lt or Methyl demeton @ 2 ml/ lt

15. Sigatoka disease

16. Mycosphaerella musicola ( Cercospora musae ) Mycosphaerella fijiensis On leaves small light yellow or brownish green narrow streaks appear. They enlarge in size becomes linear, oblong, brown to black spots with dark brown brand and yellow halo. Black specks of fungal fruitification appear in the affected leaves. Rapid drying and defoliation of the leaves

17. Survival and spread Survives on dry infected leaves on the field soil and primary infection takes place through ascospores in the infected plant debris. Secondary spread through wind borne conidia and ascospores Infection takes place through stomata on the lower surface of young leaves. Surface moisture is necessary for release of both conidia and ascospores . Hence the disease is severe in moist weather

18. Management Removal and destruction of affected leaves followed by spraying with BM (1%) + linseed oil (2%) Prevent water accumulation around the plant and go for periodical weeding. Spray [email protected]% or copper oxy [email protected]% suspended in mineral oil . Spray [email protected]% or carbendazim or thiophanate [email protected]% or [email protected]% along with spreading agent. Wetting agent such as teepol or sandovit added at the rate of 1ml/lit of water.

19. THANK YOU