pigeon pea sterility mosaic virus

symptoms, pathogen, management

1. COLLEGE OF AGRICULTURAL TECHNOLOGY Affiliated to Tamil Nadu Agricultural University, Coimbatore Kullapuram , Via Vaigai dam, Theni-625 562 PIGEON PEA STERILITY MOSAIC VIRUS SUBMITTED BY COURSE TEACHER PATHMAPRIYA. B Dr. S. PARTHASARATHY ID. No. 2016021028 Asst. Prof., (Plant Pathology )

2. Significance of SMD Sterility mosaic is an important disease of pigeon pea. Sterility mosaic disease (SMD), first described in 1931 from Pusa (Bihar, India). The sterility of plant results in yield losses of up to 100 %. Annual loss is about 2 million tons of grain in India in 1984.

3. Plants infected when less than 45 days old shows 96-100% loss in grain yield. Infection older plants results in losses varying from 27-97% loss depending on the number of branches infected per plants and show partial sterility.

4. Distribution of SMD World: Sterility mosaic is a major problem in India, Bangladesh, Myanmar, Nepal and Sri Lanka. India: The disease is present in all pigeon pea growing places of India but it is more serious in some states like Gujarat, Karnataka, Eastern Uttar Pradesh, Bihar and Tamil Nadu.

5. Worldwide distribution of major pigeon pea growing areas (red dots); sterility mosaic disease (SMD) endemic regions indicated within the blue rectangle. @https://apsjournals.apsnet.org/action/showImage?doi=10.1094%2FPDIS.2004.88.5.436&iName=master.img-001.jpg&type=master

6. Percent Incidence (PI) : Bihar (21.4%), Uttar Pradesh (12.8%), Tamil Nadu (12.2%). @https://www.youtube.com/watch?v=-Zo_RslCW4I

7. S ymptoms of SMD The disease symptoms appear in the field as pale green, stunted or bushy appearance of infected plants. Some plants exhibit clear mosaic and ring spot symptoms. The leaf size, flowers and pods are reduced. The severely infected plants do not produced flowers and pods, if formed they are sterile .

8. Symptoms of SMD @https://www.youtube.com/watch?v=-Zo_RslCW4I

9. @ https://apsjournals.apsnet.org/action/showImage?doi=10.1094/PDIS.2004.88.5.436&iName=master.img-004.jpg&w=329&h=337 Symptoms of SMD

10. Four type of symptoms appears in infected plants which are varies in the different genotypes, Severe mosaic in leaflets with complete sterility. Mild mosaic with partial sterility. Ring spot symptoms are characterized by green island surrounding by a chlorotic halo on leaflets and this symptoms disappear as the plants mature (no sterility). Masked infection without any visual symptoms .

11. @https://www.youtube.com/watch?v=dPzOvIkFtrY

12. @https://www.youtube.com/watch?v=dPzOvIkFtrY

13. @https://www.youtube.com/watch?v=dPzOvIkFtrY

14. Pathogen The disease is caused by Pigeon Pea Sterility Mosaic Virus (PPSMV). Systematic position : Group : Group V { (- ) ss RNA} Order : Bunyavirales Family : Fimoviridae Genus : Emaravirus Species : Pigeon pea sterility mosaic virus

15. Pathogen Characters T he virions are slender highly flexuous filamentous virus like particles (VLPS) of 3-10 nm diameter, a major virus specific proteins of 32kDa and 5-7 major RNA species of 0.8-6.8kb.

16. Diagrammatic representation of Pigeonpea sterility mosaic virus (PPSMV) particles @https://onlinelibrary.wiley.com/doi/pdf/10.1111/mpp.12238

17. Epidemiology PPSM virus and its vector Aceria cajani have been survived during summer in ratoon , perennial, off season and self sown volunteer pigeon pea plants. Wild pigeon pea ( Cajanus scarabaeoides ) plays important role in the survival of virus and its vector in absence of main crop in South India.

18. But in North India, wild pigeon pea are not found. Therefore it does not provide the primary inoculums to the main pigeon pea crop. Therefore, ratoon perennial, off season and self sown volunteer pigeon pea plants provide the the primary inoculums in North Indian conditions.

19. Eriophyid mite, Aceria cajani https://www.infonet-biovision.org/PlantHealth/Pests/Spider-mites

20. Vector Transmission The mite can multiply to high densities within a few weeks. These vectors are very small, measuring 200-250 μm and have a very short life of about 2 weeks. They inhabit the lower surface of the leaves. Their feeding does not cause any direct damage to the pigeon pea plants.

21. Vector Transmission The transmission efficiency of a single eriophyid mite is 53% but is 100% when >5 mites per plant are used. The acquisition feeding period are 5-10 minutes and inoculation test period are 20-30 minutes. Incubation period of virus ranges from 11-27 days. The vector can retain the virus for up to 13 hours. There is no transovarial transmission.

22. Vector Transmission Pigeonpea sterility mosaic virus is transmitted by an eriophyid mite, Aceria cajani in a semi persistent manner. This virus is transmitted by both nymph and adult mite but nymphs are more efficient vectors than adults.

23. Favourable Condition Temperature: Minimum temperature (10-15°C). Maximum temperature (25-30°C). Relative humidity ( > 60%). Rainfall have been found congenial for buildup of mite population. Wind direction and wind velocity plays important role in dissemination of virus and its vector.

24. The younger plants are more susceptible to the sterility mosaic than older plants. Disease incidence is high when pigeon peas are intercropped with sorghum or millets. Shade and humidity encourage mite multiplication. @https://www.youtube.com/watch?v=-Zo_RslCW4I

25. Management of SMD Cultural Management Rouging out infected plants up to 40 days after sowing. Early sowing and early maturing varieties crosses the most susceptible stage of the crop. Destroy the source of sterility mosaic inoculums. Remove volunteer and perennial plants of pigeon pea in the vicinity of fields.

26. Management of SMD Resistant Varieties Grow resistant varieties like - Bahar , DA-13, Pant A-3, Rampur Rahar , UPAS-120, DA-11, Bageshwari , ICPL-146, ICPL-87119 ( Asha ), ICPL 151, MA-3, BSMR-175, BSMR 736, Amar , Azad, Hy 3C, Pusa 9, MA 3 and NDA-1. VBN 1, VBN 2 and VBN 3.

27. Chemical Management Seed dressing with 25% Carbofuran ( Furadan )3G or 10% Aldicarb ( Temik ) @3 g/kg seed protect the crop upto 45 days after sowing. Soil application of Carbofuran ( Furadan ) 3G @ 1.2 kg/ha or Aldicarb ( Temik ) 10% @1.5 kg/ha protect the crop upto 75 days after sowing. Management of SMD

28. Management of SMD Chemical Management Spraying of acaricide or insecticide like Kelthane ( Dicofol ), Oxythioquinox ( Morestan ), Metasystox ( Oxydemeton -methyl) @ 0.1% to control the mite vector in early stage of plant growth. Spraying with Fenazaquin (Trick) @ 1 ml/ litre    soon after appearance of the disease and if necessary  repeat after 15 days.

29. Management of SMD @https://www.youtube.com/watch?v=-Zo_RslCW4I

30. References Sushil Kumar Singh., Dinesh Singh., and Adesh Kumar. 2015. Plant Diseases and Their Management. Kalyani Publishers, New Delhi. Singh,R.S ., 2018. Plant Diseases. Vinod Kumar Jain, Scientific International (Pvt.) Ltd, New Delhi. http://agropedia.iitk.ac.in/content/sterility-mosaic-disease-pigeonpea http://eagri.org/eagri50/PATH272/lecture14/006.html