Bacterial Leaf Blightof Rice by SACHIN R KONDAGURI.pptx

Bacterial Leaf Blightof Rice and its management in brief

1. WELCOME

2. UNIVERSITY OF AGRICULTURAL SCIENCES, BANGALORE COLLEGE OF AGRICULTURE,V C FARM,MANDYA * Submitted by : SACHIN R KONDAGURI PAMM 2030 Jr M.Sc * Submitted to : Dr.N KIRAN KUMAR Professor and Head Dept. of Plant Pathology CoA, V. C. Farm, Mandya :PRESENTATION ON BACTERIAL LEAF BLIGHT OF RICE: PAT 503 (2+1) 22-08-2023 PAMM2030 Dept. of Pathology 2

3. FLOW OF PRESENTATION 6 7 1 3 5 2 4 HISTORY SYM PTOMS INTEGRATED MANAGEMENT ECONOMIC IMPORTANCE TAXONOMY & ETIOLOGY EPIDEMIOLOGY DISEASE CYCLE

4. 22-08-2023 PAMM2030 Dept. of Pathology 4 Bacterial leaf blight Xanthomonas oryzae pv . Oryzae

5. The disease was first observed in Japan by farmers of Fukuoka (Kyushu Island,1884). The disease disseminated gradually in 1950’s throughout Japan, particularly noticed from Kyushu Island. In India, BLB was first reported in Maharashtra by Srinivasan et al. (1959) . A severe outbreak of the disease occurred in Bihar and Uttar Pradesh in 1963. 22-08-2023 PAMM2030 Dept. of Pathology 5 HISTORY

6. In general,yield losses in severely diseased fields range from 20-30% and occasionally 50%. It can destroy up to 80% of a crop if the disease develops early. In developing stage, it can nonetheless severely diminish the quality and yield of the grain. In India, millions of hectares are infected every year. yield losses have been as high as 60% in some states(AP). Godavari district of Andhra Pradesh which are endemic to this disease. Taichung Native 1 is highly susceptible. 22-08-2023 PAMM2030 Dept. of Pathology 6 ECONOMIC IMPORTANCE

7. The symptoms are appearing in 2 stages: 1) Seedling wilt ( kresek ). Observed 1-3 weeks after transplanting Appearance of green water-soaked layer along the cut portion or leaf tip of leaves as early symptom Leaves wilt and roll up and become grayish green to yellow colour Entire plant will wilt completely 22-08-2023 PAMM2030 Dept. of Pathology 7 SYMPTOMS Seedling wilt- Kresek

8. 2) Leaf blight Water-soaked yellowish lesions on leaf blades starting at leaf tips with a wavy margin Drying of leaves back from tip and curling, leaving mid rib intact are the major symptoms. Appearance of bacterial ooze that looks like a milky or opaque dewdrop on young lesions early in the morning Severely infected leaves tend to dry quickly They dry up on the surface leaving a white encrustation. The affected grains have discoloured spots surrounded by water soaked areas. If the cut end of leaf is dipped in water, bacterial ooze makes the water turbid. 22-08-2023 PAMM2030 Dept. of Pathology 8

9. 22-08-2023 PAMM2030 Dept. of Pathology 9 Snake hood symptom

10. 22-08-2023 PAMM2030 Dept. of Pathology 10 Drying of leaves back from tip and curling

11. Kingdom: Bacteria Phylum : Pseudomonadota Class : Gammaproteobacteria Order : Xanthomonadales Family : Xanthomonadaceae Genus : Xanthomonas Species : oryzae 22-08-2023 PAMM2030 Dept. of Pathology 11 TAXONOMY

12. The bacterium is strict aerobe, gram negative. Non spore forming, rod shaped(1.2 x 0.3-0.5 µm) with monotrichous polar flagellum at one end. The bacterial cells are capsulated and are joined to form an aggregate mass. 22-08-2023 PAMM2030 Dept. of Pathology 12 ETIOLOGY Microscopic view

13. 22-08-2023 PAMM2030 Dept. of Pathology 13 Colonies are circular, convex with entire margins, whitish yellow to straw yellow and opaque. The bacterium has many strains that differ in ability to infect rice plants. Strains in tropical countries are usually more virulent than those in temperate areas like Japan. Culture plate of BLB

14. 22-08-2023 PAMM2030 Dept. of Pathology 14 Electron microscopic view of Xoo

15. BLB is primarily a vascular or systemic disease. The primary source of infection is through bacterium overwintering in seed (husk and endosperm). Bacteria may survive in soil, plant stubbles and debris.The bacterium enters the plant through water pores ( hydathodes ) along the edges of the leaf and through injuries in roots or leaves. It does not enter through stomata. Bacterial cells move along the vascular tissues causing wilting. Rain storms and typhoons help in the spread of the disease. Irrigation water also carries the organism from field to field. 22-08-2023 PAMM2030 Dept. of Pathology 15 DISEASE CYCLE

16. The pathogen also survives on collateral hosts like Leersia hexandra , Leersia oryzoides , Zizania latifolia , Cyprus rotundus , Cyprus deformis , Phalaris arundinacea , Cyanodon dactylon , etc. The bacterial ooze serves as secondary inoculum and cause secondary infection. 22-08-2023 PAMM2030 Dept. of Pathology 16

17. 22-08-2023 PAMM2030 Dept. of Pathology 17 DISEASE CYCLE Source: Research gate

18. Clipping of tip of the seedlings while transplanting. Warm temperature( 25-30° C ), high humidity, rain and deep water. Presence of collateral weeds Presence of rice stubbles and ratoons of infected plants Severe winds , which cause wounds, and over fertilization are suitable factors for the development of the disease. Irrigation water and splashing or windblown rain can disseminate the bacterium from plant to plant. The use of trimming tools for transplanting and by handling during transplanting can also trigger new infection. 22-08-2023 PAMM2030 Dept. of Pathology 18 FAVOURABLE CONDITIONS

19. Avoid clipping of seedlings during transplanting. Grow nurseries preferably in isolated upland conditions Balanced fertilization , avoid excess N-application and skip N - application at booting (if disease is moderate) Drain the field (except at flowering stage of the crop) Destruction of weeds and collateral hosts Avoid flow of water from affected fields Maintain proper plant spacing Secure disease free seed Affected stubbles are to be destroyed by burning or through ploughing 22-08-2023 PAMM2030 Dept. of Pathology 19 INTEGRATED MANAGEMENT CULTURAL:  

20. Seed treatment - seed soaking for 8 hours in Agrimycin (0.025%) and wettable ceresan (0.05%) followed by hot water treatment for 30 min at 52-54 o C Seed treatment with zinc sulfate (2%) reduce bacterial blight. 22-08-2023 PAMM2030 Dept. of Pathology 20 PHYSICAL:   Grow resistant cultivars like Pusa basmati 1 , Jyothi , MTU 9992 , Swarna , Ajaya , IR 20 , IR 42, IR 50, IR 54, TKM 6, Mashuri , IET 4141, IET 1444, IET 2508, Chinsura Boro , etc. HOST RESISTANCE:  

21. 22-08-2023 PAMM2030 Dept. of Pathology 21 CHEMICAL:   Spray Neem oil 3% or NSKE 5% Spray Streptocycline (250 ppm) along with Copper oxychloride (0.3%) Seed treatment with bleaching powder (100g/l) and zinc sulfate (2%) reduce bacterial blight. BIOLOGICAL:   Seed treatment with pseudomonas fluorescens i.e., 10g/kg of seeds and spray @10 8 cfu/ml

22. 22-08-2023 PAMM2030 Dept. of Pathology 22 Spray Streptomycin sulphate + Tetracycline combination 300 g + Copper oxychloride 1.25kg/ha. If necessary repeat 15 days later. Application of bleaching powder @ 5 kg/ha in the irrigation water is recommended in the kresek stage. Two spray of Nano copper @0.2 ppm at 15 days interval starting from active tillering stage

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