• Diagnosis of Rice diseases and management
• Host plant resistance for fungal and viral pathogens
• Molecular studies of fungal pathogens
• Molecular plant virology
• Diagnosis of cotton diseases and management

• Standardized the mechanical inoculation techniques for TSV: Standardized the sap inoculation procedure of the virus.  The cowpea (CO 7) plants were raised in the glasshouse under insect proof conditions. The virus extract was prepared by macerating TSV infected leaf samples (Gossypium barbadense- CCB 29, ICB 25 and Suvin) with 0.1 M sodium phosphate buffer pH 7.0 and 0.1 M Potassium phosphate buffer pH 7.0 using ice tray and inoculated mechanically in cowpea cotyledonary leaves of six-day old plants previously dusted with 600 mesh carborundum powder. The inoculated plants were kept under observation for 4 to 5 days for the expression of symptoms. TSV symptoms with necrotic and chlorotic symptoms with systemic nature were observed on cowpea seedlings at 3 to 7 days after inoculation. 
• Novel and standardized screening method for TSV: A total of 300 germplasm lines of Gossypium barbadense were evaluated through two-season natural screening for Tobacco Streak Virus (TSV) during 2018–2019 and 2019–2020. From this evaluation, 14 resistant and 94 susceptible lines were identified and further validated in 2020–2021 under separate screening conditions. Fourteen germplasm lines viz., ICB 84, 85, 86, 87, 90, 91, 122, 124, 125, 127, 153, 161, 162, and 163 were confirmed as resistant (disease grade 1). Among these, five superior lines (ICB 162R, ICB 163R, ICB 124R, ICB 122R, and ICB 127R) were advanced during 2024-2025 for their enhanced biometric performance. The line ICB 162R exhibited minimum TSV incidence, improved growth traits, and the highest seed cotton yield (89.2 g/plant) with only 17% yield loss. Correlation analysis revealed a strong association between TSV incidence and yield loss. This study led to the development of a novel and standardized screening method for evaluating TSV resistance in cotton, the first of its kind-significantly contributing to resistance breeding programs in G. barbadense.
• Standardized Artificial inoculation of rust spores over cotton: Hydrofluoroether (NovecTM 7100)- Sigma Aldrich- most efficient chemicals to facilitate penetration of the spores into leaf surface. In this method, rust spores were mixed with (hydrofluoroether and obtained solution is sprayed with the aid of airbrush spray gun to cotton plants at different day period. Spraying of rust spores with hydrofluoroether resulted in the lesion appearance within 8 days of its spray, 15 days for pustule formation and 18 days for pustule eruption. The spores per pustule observed as 55 and lesion diameter (µm) as 325. The method was successfully standardized and found reproducible across all inoculation timings, providing a reliable and precise technique for studying rust pathogenesis and screening cotton genotypes for rust resistance.
• Molecular Detection and Characterization of the Pathogen: DNA extraction from all rust samples were carried out using cetyltrimethyl ammonium bromide (CTAB) by modifying the spore extraction process. PCR amplification with ITS primers produced ~650 bp fragments in all fifteen isolates. Further amplification using PGV1–PGV2 and PGV3–PGV4 primer pairs yielded fragments of ~647 bp and ~602 bp, respectively, confirming the identity of the pathogen as Phakopsora gossypii. Sequences of representative isolates PG1 and PG2, amplified with ITS primers, were submitted to GenBank under accession numbers PV523281 and PV834854. This study successfully established a molecular detection and characterization protocol for P. gossypii, providing a reliable diagnostic tool for rust identification and aiding in molecular diversity studies of the pathogen
• Influence of Weather Variables on Rust Disease Development: A comprehensive regression analysis was conducted to determine the influence of weather parameters on the development of cotton rust disease. Multiple regression analysis of pooled data indicated that morning relative humidity, sunshine hours, and windspeed significantly affected disease progression. Independent t-tests confirmed strong correlations (p < 0.05) between Percent Disease Index (PDI) and weather variables, including maximum temperature, relative humidity (morning/evening), and windspeed. High R² values (0.72–0.87) demonstrated good model fit, indicating that the regression models effectively captured the variability in disease incidence due to weather factors. Positive trend lines for windspeed and minimum temperature against PDI in RCH 659 BG II and Suraksha confirmed their conducive role in rust spread, while other variables showed negative associations. This study established a quantitative model for predicting cotton rust outbreaks, enhancing understanding of disease-weather interactions and supporting early warning and management strategies for sustainable cotton production.
• Field evaluation of fungicides against Phakopsora gossypii: A field experiment was conducted on hybrid RCH 659 BG II using a Randomized Block Design (RBD) with three replications to evaluate the efficacy of fungicides against Phakopsora gossypii. The treatments included seven fungicidal formulations, Kresoxim-methyl, Propiconazole, Propineb, Fluxapyroxad + Pyraclostrobin, Azoxystrobin + Difenoconazole, Metiram + Pyraclostrobin, and Carbendazim + Mancozeb along with an untreated control. Among the treatments, Fluxapyroxad 167 g/L + Pyraclostrobin 333 g/L SC @ 0.6 mL/L recorded the lowest rust disease intensity (11.3%), achieving 67.9% disease reduction over control and the highest seed cotton yield of 838.4 kg/ha. This field validation demonstrated the superior performance of Fluxapyroxad + Pyraclostrobin for effective management of cotton rust, contributing valuable insights for integrated disease management and enhancing yield stability under field conditions.
• Resistance screening for TSV: Totally five lines viz., ICB 162R, ICB 163R, ICB 124R, ICB122R and ICB 127 R were selected as resistant with improved biometric parameters. Biometric parameters observed in resistant and susceptible lines showed that ICB 162R recorded less TSV disease incidence with increased parameters as plant height, no. of bolls and further recorded higher seed cotton yield of 89.2 g/plant with less reduction in yield loss of 17%. The correlation data shows that TSV incidence correlate with % yield loss.

Sequences submitted in NCBI:

• Submitted nucleotide Tobacco streak virus isolate TSV GB 1 coat protein gene, partial cds (GenBank accession number: MN631093) published on 10.08.2020
• Submitted nucleotide Tobacco streak virus isolate TSV GB 2 coat protein gene, partial cds (GenBank accession number: MN631094) published on 10.08.2020
• Submitted nucleotide Phakopsora gossypii isolate PG 1 large subunit ribosomal RNA gene, partial sequence (GenBank accession number: PV523281) published on 21.04.2025. 
• Submitted nucleotide Phakopsora gossypii isolate PG 2 large subunit ribosomal RNA gene, partial sequence (GenBank accession number: PV834854) published on 02.07.2025

• National Conference on “Recent Advances in Plant Pathology and Innovative Approaches in Plant Disease Management (RAPPID)” jointly organized by IPS Central Zone at PJTSAU, Hyderabad from 12-13 December 2024
• National Workshop on “Cotton Yield Improvement Through High-Density Planting System (HDPS)” jointly organized by ICAR-CICR with the support of FSII and NSAI at Le Meridien, Nagpur on 7 March 2025
• X^th International Conference in Hybrid Mode on Global Research Initiatives for Sustainable Agriculture & Allied Sciences (GRISAAS-2025) by Astha Society at MPUAT, Udaipur, Rajasthan, India from 05-07 October 2025
• Indo-French seminar on “Interface of Plant Disease Epidemics, Food Safety, and Food Security: Implications for One Health” at TNAU, Coimbatore from 12 to 14 November 2025
• 9^th International Conference in Hybrid Mode on Advances in Agricultural, Biological and Biodiversity Conservation for Sustainable Development (ABCD-2025) at University of Mysore, Karnataka from 13 to 15 November 2025
• National Conference on “Transforming Plant Health Management: Integrating Traditional Practices with Modern Innovations for Global Food Security” at PAJANCOA & RI, Karaikal, Puducherry from 18-19 December 2025

TRAINING ATTENDED

• Attended ICAR sponsored short course training on “Volatilomics: A key to understand plant-microbe interactions and stress management in crop plants for a greener tomorrow” organised by department of agricultural microbiology, TNAU, Coimbatore from 1 to 10 February 2024.

TRAINING CONDUCTED

• Acted as co-convener for “Institutional Attachment of B.Sc. (Hons) Agricultural Students (110)” from Amrita School of Agricultural Sciences, Coimbatore under RAWE from 24 to February 2025.

INVITED LECTURES 

• Acted as Keynote speaker and addressed on “Necrosis disease of cotton: an emerging threat and its management” at CEFIPRA-funded Indo-French seminar on “Interface of Plant Disease Epidemics, Food Safety, and Food Security: Implications for One Health” at TNAU, Coimbatore from 12 to 14 November 2025.

• NESA scientist of the year award-2023 
• Best oral presentation as co –authored in the paper presented during IPS 2021
• Certificate of merit (with distinction) for attending the virtual workshop on “ABC of scientific writing” organized by ICAR-NRRI, Cuttack,2020
• Young scientist award by Astha foundation-2020
• NESA young scientist of the year award-2020
• Young scientist award sponsored by Society for Scientific Development in Agriculture & Technology, 2016.
• Best poster commendation award sponsored by Indian Phytopathological Society, 2016
• IVS-Young scientist award sponsored by Indian Virological Society, 2014
• Third rank holder in Plant Pathology- Agricultural Research Service (ARS) exam, 2013
• Qualified the National Eligibility Test (NET) in Crop Protection conducted by Agricultural Scientist Recruitment Board (ASRB)- ICAR, India, 2012
• INSPIRE JUNIOR RESEARCH FELLOW (PROFESSIONAL) sponsored by Dept. of Science and Technology, Govt. of India, New Delhi, 2010
• Dr. K. Balaraman award for the best student in Plant Protection Studies, 2010
• Prof. K. Ramakrishnan award for the best student in Plant Pathology, 2010
• TNAU First rank holder in Post graduation, 2010
• TNAU Merit Scholarship holder in Post graduation, 2008

RESEARCH ARTICLES – INTERNATIONAL JOURNAL

• Valarmathi, P and R. Rabindran. 2015. Nested PCR assay for detection of Rice Orange Leaf phytoplasma in the Zigzag leafhopper vector, Recilia dorsalis (Motschulsky): a first report. The Ecoscan, 9(3&4): 837-839 (NAAS: 4.65)
• Valarmathi, P., G. Kumar, S. Robin, S. Manonmani, I. Dasgupta and R. Rabindran. 2015. Evaluation of virus resistance and agronomic performance of rice cultivar ASD 16 after transfer of transgene against Rice tungro bacilliform virus by backcross breeding. Virus Genes, 52(4):521-529 (NAAS: 8.2)
• Singh Kartar, Valarmathi, P, Sharma Sapna, Bashyal Bishnu Maya, Gurjar Malkhan Singh and Aggarwal Rashmi. 2016. Association of melanin content with pathogenicity and virulence in Bipolaris oryzae. Research Journal of Biotechnology. Vol. 11 (9): 37-42 (NAAS: 6.24)
• Kumar, G., Jyothsna, M., Valarmathi, P., Roy, S., Banerjee, A., Tarafdar, J., Senapati, B.K., Robin, S., Manonmani, S., Rabindran, R. and Dasgupta. I. 2019. Assessment of Resistance to Rice Tungro Disease in Popular Rice Varieties in India by Introgression of a Transgene against Rice Tungro Bacilliform Virus. Archives of Virology. 164: 1005–1013. https://doi.org/10.1007/s00705-019-04159-3 (NAAS: 8.69)
• Magudeeswari, P., Balakrishnan, D., Surapaneni, M., Krishnam Raju, A., Venkat Rao, Y. Pranay, G., Valarmathi, P., Bhadana, V.P., Neelamraju, S. and Sundaram, R.M. 2024. Exploring stable low soil phosphorous stress tolerance in Rice using Novel Allele Recombination from Oryza rufipogon. Plant Breeding, 1–19. https://doi.org/10.1111/pbr.13238 (NAAS: 7.5)
• Renuka, R., Anandhan, T., Valarmathi, P., Lakshmipriya, S., Vengadessan, V. and Umamaheswari, D. 2025. Translating multi-omics insights into Rice Disease Management: Integrative approaches for sustainable resistance. Physiological and Molecular Plant Pathology, 138: 102694.  https://doi.org/10.1016/j.pmpp.2025.102694. (NAAS: 8.8)
• Valarmathi, P. and Amutha, M. 2025. Field evaluation of germplasm lines of extra-long staple cotton (Gossypium barbadense) for tobacco streak virus resistance. Euphytica. 221: 140. https://doi.org/10.1007/s10681-025-03586-5 (NAAS: 7.9) 

RESEARCH ARTICLES – NATIONAL JOURNAL

• Valarmathi, P., Velazhahan, R., Seetharaman, S., Sabariappan, R., Rabindran, R. and Govind P. Rao. 2015. Subgroup level identification of rice orange leaf phytoplasma and its natural transmission through zigzag leafhopper (Recilia dorsalis) in India. Phytopathogenic Mollicutes, 5(2): 107-112 (NAAS: 5.17)
• Valarmathi, P. and Dhamayanthi, K.P.M. 2020. Occurrence and distribution of tobacco streak virus (TSV) in the germplasm of ELS cotton Gossypium barbadense. Journal of cotton research development. 34 (1) 92-98 (NAAS: 4.7)
• Valarmathi, P. 2020. Host range studies of Tobacco Streak Virus infecting Cotton. Annals of Plant Protection Science. 28 (2): 147-150. doi: 10.5958/0974-0163.2020.00039.7 (NAAS: 4.82)
• Valarmathi, P. and Dhamayanthi, K.P.M. 2020. Serological assay of Tobacco streak virus (TSV) in the different plant parts of germplasm and advance generations of Gossypium barbadense. Indian Journal of Plant Protection. 48 (3):206-209 (NAAS: 4.94)
• Valarmathi, P., Kanjana, D. and Sankaranarayanan, K. 2025. Influence of Weather Variables on Progression of Rust Disease (Phakopsora gossypii) in Cotton. Agricultural Science Digest, 1-7. https://doi: 10.18805/ag. D-6226 (NAAS:5.52)

BOOKS

• Valarmathi, P and Chandrasekar, G. 2013. Management of Grapes downy mildew- A Devastating Disease. LAB LAMBERT Academic Publishing, Deutschland/Germany. ISBN: 978-3-659-36277-4

BOOK CHAPTERS AND CONFERENCE PROCEEDINGS

• P. Valarmathi and D. Ladhalakshmi. 2020. Molecular studies of Zig zag leaf hopper (Recilia dorsalis) causing Rice Orange leaf phytoplasma In Payir noykal. Editors: Drs. Sudha, A., Rajesh, M., Sudin Raj, T. and Muthu Kumar, A. Agricultural Scientific Tamil Society, New Delhi-110 012, India. 209-212p.
• S. K. Sain., Gulsar Banu., P. Valarmathi., S.P. Gawande., D.T. Nagrale., N.S. Hiremani., D. Monga, Mujeebur Rahman Khan and Rahul Kumar Sharma. 2021. COTTON: Important Disease and Nematode Problems. In Diseases of Nationally Important Field Crops. Editors: M.R. Khan, Z. Haque and F. Ahamad. Today & Tomorrow’s Printers and Publishers, New Delhi – 110 002, India. 501-537p.
• Manish Kumar, Yunfeng Wu, Peiwen Gu, Trinh Xuan Hoat, P. Valarmathi and G.P. Rao. 2023. Updates on phytoplasma diseases associated with cereals in Asia. In Phytoplasma Diseases of Major Crops, Trees, and Weeds. Editors: A.K. Tiwari, K. Caglayan, T.X. Hoat, Ali-Al Subhi, N. Nejat and Gurivi Reddy. Academic press, An imprint of Elsevier, United Kingdom. 1-18p. ISBN: 978-0-323-91897-8. https://doi.org/10.1016/B978-0-323-91897-8.00018-6.
• D. Kanjana, J. Annie Sheeba, P. Valarmathi, S. Usha Rani and N. Malaichamy. 2024.   Integrated Nutrient Management for cotton production. In Vazhvai Viruthiyaakkum Paruthi (Prosperous through Cotton)-Technical Guide to Cotton stakeholders (Eds.) S. Usha Rani, A. Sampathkumar, M. Sabesh, A.H. Prakash, T.N. Sujeetha, M. Sathishkumar, G. Suresh. (Tamil) by ICAR – Central Institute for Cotton Research, Regional Station, Coimbatore. 68-72p
• M. Amutha, D. Kanjana, J. Annie Sheeba, P. Valarmathi and S. Usha Rani. 2024. Emerging insect pests of cotton and their management. In Vazhvai Viruthiyaakkum Paruthi (Prosperous through Cotton)- Technical Guide to Cotton stakeholders (Eds.) S. Usha Rani, A. Sampathkumar, M. Sabesh, A.H. Prakash, T.N. Sujeetha, M. Sathishkumar, G. Suresh. (Tamil) by ICAR – Central Institute for Cotton Research, Regional Station, Coimbatore. 94-103p
• A. Sampathkumar, P. Valarmathi, S. Usha Rani, T.N. Sujeetha, M. Sathishkumar and G. Suresh. 2024. Cotton diseases and its integrated disease management. In Vazhvai Viruthiyaakkum Paruthi (Prosperous through Cotton)-Technical Guide to Cotton stakeholders (Eds.) S. Usha Rani, A. Sampathkumar, M. Sabesh, A.H. Prakash, T.N. Sujeetha, M. Sathishkumar, G. Suresh. (Tamil book) by ICAR – Central Institute for Cotton Research, Regional Station, Coimbatore. 132-147p
• P. Valarmathi and A. Sampathkumar. 2024. Cotton Necrosis Disease (Tobacco Streak Virus): Symptoms and its integrated management. In Vazhvai Viruthiyaakkum Paruthi (Prosperous through Cotton)-Technical Guide to Cotton stakeholders (Eds.) S. Usha Rani, A. Sampathkumar, M. Sabesh, A.H. Prakash, T.N. Sujeetha, M. Sathishkumar, G. Suresh. (Tamil) by ICAR – Central Institute for Cotton Research, Regional Station, Coimbatore. 148-152p

PAPER PRESENTED IN CONFERENCE/ SEMINAR / SYMPOSIA 

International:

1. Oral presentation on “Emergence of Cotton Rust Caused by Phakopsora gossypii in South India: A Growing Threat” at X^th International Conference in Hybrid Mode on “Global Research Initiatives for Sustainable Agriculture & Allied Sciences (GRISAAS-2025)” held at MPUAT, Udaipur, Rajasthan from 05-07 October 2025.
2. Oral presentation on “Necrosis disease of Cotton: an emerging threat and it’s management” at Indo-French Seminar on “Interface of Plant Disease Epidemics, food safety and food security: implications for one health” held at TNAU, Coimbatore from 12-14 November 2025
3. Oral presentation on “Current Status of Rice Viral Diseases with special reference to Rice Tungro Disease” at 9th International Conference in Hybrid Mode on Advances in Agricultural, Biological and Biodiversity Conservation for Sustainable Development (ABCD-2025) held at University of Mysore, Karnataka from 13 to 15 November 2025

National:

1. Oral presentation on “Unravelling the Interaction of Rice Tungro Disease with Rice Phytoplasmas and its Transgenic Resistance” at IPS Central Zone Meet and DSPP National Conference on “Recent Advances in Plant Pathology and Innovative Approaches in Plant Disease Management (RAPPID)” held at PJTSAU, Hyderabad from 12-13 December 2024
2. Oral presentation on “Evaluation of Gossypium barbadense germplasm for tolerance to Tobacco Streak Virus and Thrips in field conditions” at National Conference on “Transforming Plant Health Management: Integrating Traditional Practices with Modern Innovations for Global Food Security” held at PAJANCOA & RI, Karaikal, Puducherry from 18-19 December 2025
3. Oral presentation on “Tobacco Streak Virus-induced necrosis in Cotton: symptom expression and disease progression in Gossypium barbadense” at National Conference on “Transforming Plant Health Management: Integrating Traditional Practices with Modern Innovations for Global Food Security” at PAJANCOA & RI, Karaikal, Puducherry during 18-19 December, 2025

POPULAR ARTICLES/ SHORT NOTES/ SHORT COMMUNICATIONS 

• Valarmathi, P. and Prakash, A.H.  2023. Cotton Necrosis Disease caused by Tobacco Streak Virus (TSV): an emerging threat to cotton growing areas of South India. CAI- Cotton Statistics & News. Vol. 16:05-07.  
• Valarmathi, P. 2023. Status on cotton leaf roll dwarf disease in cotton. COTTON innovate. Vol. 07(3): 1-2.
• Valarmathi, P. and Kanjana, D. 2024. Nanoparticles: as protectants in plant disease management. AGROBIOS Newsletter. Vol. XXII (8): 37-38
• Valarmathi, P. and Kanjana, D. 2024 Chitosan for Eco-Friendly Management of Plant Diseases. AGROBIOS Newsletter. Vol. XXII (10): 11-13
• Valarmathi, P., Kanjana, D. and Amutha, M. 2024. Disease Management in Organic Cotton cultivation. AGROBIOS Newsletter. Vol. XXII (12): 44-45
• Valarmathi, P. and Kanjana, D. 2024. Challenges in the application of drones in detection of plant diseases. AGROBIOS Newsletter. Vol. XXIII (3): 45-46
• Valarmathi, P. 2025. Nanoparticles for the management of plant virus. AGROBIOS Newsletter. Vol. XXIV (4): 29-30 (04.08.2025)
• Valarmathi, P. 2025. Bacteriophage-based biosensors and bioassay for detection of plant-pathogenic bacteria. AGROBIOS Newsletter. Vol. XXIV (5): 23-24
• Valarmathi, P. and Kanjana, D. 2025. Antimicrobial activity of chitosan against phytopathogens. AGROBIOS Newsletter. Vol. XXIV (6): 16-17 (03.11.2025)
• Valarmathi, P. and Kanjana, D. 2025. Effect of organic amendments on soil borne pathogens. AGROBIOS Newsletter. Vol. XXIV (7): 5-6
• Valarmathi, P. 2025. Phakopsora gossypii inciting rust disease: an emerging challenge in South India’s cotton region. Cotton Innovations, International Cotton Researchers Association, Vol. 5 (7): 15-20. ISSN 2788-6611

RESEARCH BULLETIN/ EXTENSION BULLETINS 

• Laha, G. S., Sailaja, B., Srinivas Prasad, M., Ladhalakshmi, D., Krishnaveni, D., Singh Ram, Prakasam, V., Yugender, A., Kannan, C., Valarmathi, P. and Ravindra Babu, V. 2016. Changes in rice disease scenario in India: An analysis from Production Oriented Survey.  Technical Bulletin No. 91. ICAR- Indian Institute of Rice Research (IIRR), Rajendranagar, Hyderabad-500 030, Telangana, India, 95pp.
• D. Krishnaveni, M. Srinivas Prasad, G.S. Laha, C. Kannan, D. Ladhalakshmi, V. Prakasam and
  P. Valarmathi. 2016. Vari Nasinchu Thegullu-Yajamanya Paddhathulu In: Adhika Vari Dhigubaduluku Aadhunika Saankethika Suchanalu (Telugu) Bulletin published by ICAR- Indian Institute of Rice Research (IIRR), Rajendranagar, Hyderabad- 500 030, India. P 60-64.

• Life member, Indian Phytopathological Society (IPS), New Delhi
• Life member, Indian Virological Society (IVS), New Delhi
• Life member, Cotton Research and Development Association (CRDA), Haryana
• Life member, Indian Society of Cotton Development (ISCI), Mumbai
• Life member, Society for Advancement of Rice Research (SARR), Hyderabad
• Life member, Indian Society of Mycology and Plant Pathology (ISMPP), Rajasthan
• Life member, Plant Protection Association of India (IJPP), Hyderabad
• Member, International Cotton Researchers Association (ICRA)
• Life member, National Environmental Science Academy (NESA), New Delhi
• Life member, “Valarum Velanmai”, TNAU

• Member, Institute Research Committee (IRC) and PIMS
• Member, Human Resource Development Cell
• Member, Farm Advisory Committee (FAC)
• Member, Application screening committee (YP-I/YP-II/SRF)

Mera Gaon Mera Gaurav

I certify that the above information is correct to the best of my knowledge.

Date: 11.02.2026                                                                                                                    Dr. P. Valarmathi