Brinjal bacterial wilt

BRINJAL BACTERIAL WILT, CAUSAL ORGANISM, SYMPTOMS AND MANAGEMENT

1. COLLEGE OF AGRICULTURAL TECHNOLOGY ( Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 BRINJAL BACTERIAL WILT Ralstonia solanacearum Course teacher: Name: Dr.Parthasarathy.S , Nainu Joseph Asst. Professor (Plant Pathology) 2015021088

2. CONTENT OCCURRENCE LOSSES SYMPTOMS PATHOGEN SYSTEMATIC POSITION MODE OF SPREAD AND SURVIVAL FAVOURABLE CONDITIONS MANAGEMENT

3. OCCURRENCE It is endemic to the southern United States as well as Africa, Asia and South America.  Ralstonia  spp. is prevalent in tropical and subtropical regions of the world. I t has recently become a recognized problem in temperate regions as well.

4. OTHER HOSTS Plant hosts that  R. solanacearum  infects include: Potato ,tomato , banana, ginger, tobacco, sweet pepper ,olive ,rose ,soybean. LOSSES In India loss in yield in brinjal is upto 8.1 per cent.

5. SYMPTOMS Sudden wilting of affected plants. Characteristic symptom is drooping of young top leaves and shoots of the plants. Water soaked areas in form of black streaks are often noticed on stem. In severe cases these areas rot and bacterial ooze out is noticed.

6. Infected region of the stem or root shows brown discolouration in vascular region and bacterial ooze out in form of milky white stream. The plants die within 3 to 5 days after appearance of first symptom. The disease is severe during monsoon when fields are waterlogged.

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9. PATHOGEN Rod shaped with tuft of polar flagella. Gram negative bacteria. R. solanacearum  is soil-borne and  motile with a  polar flagellar tuft. It colonizes the  xylem, causing bacterial  wilt  in a very wide range of potential host plants.

10. SYSTEMATIC POSITION Domain : Bacteria Phylum : Proteobacteria Class : Betaproteobacteria Order : Burkholderiales Family :   Burkholderiaceae Genus : Ralstonia Species : R. solanacearum

11. MODE OF SPREAD AND SURVIVAL The bacterium though a non-spore former is found to be alive and viable for more than 16 months in laboratory condition. It s found alive in infected plant debris for 10 months. Presence of Meloidogyne javanica increases the wilt incidence.

12. FAVOURABLE CONDITIONS Symptom expression is favored by high temperatures ( 30-35˚C ) and symptoms of the disease may progress rapidly after infection . High soil moisture and periods of wet weather or rainy seasons are associated with high disease incidence.

13. MANAGEMENT PHYSICAL METHODS Rouging of diseased plants and burn. Field sanitation by ensuring weed free field. RESISTANT VARIETY Use resistant variety namely Pant Samrat , Arka Keshav , Arka Neelkant , Pusa Purple Cluster and Pusa Purple Round, etc. Avoid susceptible varieties like Pusa Purple Long.

14. CULTURAL METHODS Summer p loughing . Crop rotation with cereals or cruciferous vegetables. Solarization of nursery beds. Keep land fallow for a season to destroy harmful pathogens. Avoid water logging and provide drainage facility.

15. BIOLOGICAL METHOD Apply neem cake @ 100 kg /acre to reduce bacterial pathogen. Apply basally talc based Pseudomonas fluorescens at 2.5 kg/ ha pre-colonized in farm yard manure.

16. CHEMICAL METHOD Soil fumigation with Formalin at 7% before sowing. Seed treatment with Streptocycline (150 ppm ) for 90 min. Spray copper fungicide to control disease (2% Bordeaux mixture). Drench in and around diseased area with copper hydroxide 77%WP @ 3 g/ litre .

17. REFERENCE V. K Gupta and Y. S Pacil . Diseases of vegetable crops – published by Kalyani publishers, New Delhi. Page no: 121-124 T. S Thind , Diseases of fruits and vegetables and their management- Kalyani publishers, New Delhi. Page no: 373 http://www.kisansuvidha.com/brinjal-diseases Plant pathology journal- Some Important Plant Pathogenic Disease of Brinjal and their Management.