Study of Characterization and Population Dynamics of Paddy Nematodes in the North-West Agro-Climatic Zone of Bihar, India

Plant-parasitic nematodes are a major constraint to rice production, leading to significant yield losses under diverse agro-ecological conditions. A systematic survey was conducted in the North-West agro-climatic zone of Bihar during 2022–2024 across both Kharif and Rabi seasons to assess nematode diversity, distribution, and population dynamics in paddy fields. A total of 286 composite soil and root samples were collected and processed using Cobb’s sieving and decanting method followed by the modified Baermann funnel technique. Four major nematode species were identified: Meloidogyne graminicola, Hirschmanniella oryzae, Aphelenchoides besseyi, and Ditylenchus angustus. Among these, M. graminicola was the most dominant species, recorded in 78.3% of the samples. Nematode population density ranged from 96 to 515 individuals per 200 cc soil, with peak populations observed during the Kharif season. Sandy loam soils and moderate moisture conditions were found to favor higher nematode infestation, whereas relatively lower populations were recorded in clay loam and continuously flooded conditions. Statistical analysis revealed a strong positive correlation between nematode population density and yield loss (r = 0.82), supported by a linear regression model indicating progressive yield reduction with increasing nematode population. Yield losses ranged from 28% under moderate infestation to 65% in severely affected fields. Minor genera such as Tylenchorhynchus and Helicotylenchus were also recorded, often in association with dominant species, suggesting their contributory role in overall plant stress. The study highlights the widespread occurrence and ecological significance of plant-parasitic nematodes in the region and emphasizes the need for location-specific integrated management strategies for sustainable rice production.

Paddy, nematodes, Bihar, population dynamics, Meloidogyne graminicola

1. Arun, A., Shanthi, A., Raveendran, M., Seenivasan, N., Pushpam, R., & Shandeep, G. (2023). An insight into occurrence, biology, and pathogenesis of rice root-knot nematode Meloidogyne graminicola. Biology, 12(7), 987. https://doi.org/10.3390/biology12070987 [Google Scholar] [Crossref]

2. Bridge, J., Plowright, R.A. & Peng, D. (2005). Plant parasitic nematodes in subtropical and tropical agriculture. CAB International. [Google Scholar] [Crossref]

3. Gautam, V., Nagar, R., Barai, P., Garg, V., Singh, S., Patel, S., & Singh, R. K. (2024). Exploring the rice root metabolome under stress of Meloidogyne graminicola. Plant Stress, 14, 100620. [Google Scholar] [Crossref]

4. Hada, A., Dutta, T. K., Singh, N., Singh, B., Rai, V., Singh, N. K., & Rao, U. (2020). Genome-wide association study for resistance to Meloidogyne graminicola in Indian rice. PLOS ONE, 15(9), e0239085. [Google Scholar] [Crossref]

5. Khan, M. R. (2021). Biomanagement of rice root-knot nematode using microbial isolates. Journal of Applied Microbiology, 130(2), 424–438. [Google Scholar] [Crossref]

6. Khan, M.R., Altaf, S. & Kumar, V. (2023). Impact of root-knot nematode (Meloidogyne graminicola) on rice productivity and its management. Indian Journal of Nematology, 53(1), 45–52. [Google Scholar] [Crossref]

7. Kumar, A. & Prasad, D. (2024). Population dynamics of plant-parasitic nematodes in rice-based cropping systems of eastern India. Journal of Applied and Natural Science, 16(1), 112–118. [Google Scholar] [Crossref]

8. Kumar, S., Singh, R. & Meena, R.S. (2022). Seasonal incidence of nematodes in rice fields under varying agro-climatic conditions. Indian Phytopathology, 75(2), 233–240. [Google Scholar] [Crossref]

9. Mahalik, J. K., Nayak, G., Das, S., & Rout, D. S. (2024). Efficacy of fluopyram against Meloidogyne graminicola in rice. Indian Journal of Nematology, 54(1), 78–81. [Google Scholar] [Crossref]

10. Prasad, B., Yadav, S.K. & Singh, P. (2023). Influence of soil properties on nematode distribution in agricultural fields. Journal of Soil Biology and Ecology, 43(2), 89–96. [Google Scholar] [Crossref]

11. Prot, J.C. & Matias, D.M. (1995). Effect of water regime on nematode populations in irrigated rice fields. Fundamental and Applied Nematology, 18, 359–369. [Google Scholar] [Crossref]

12. Singh, R., Kumar, V. & Sharma, A. (2021). Ecology and distribution of rice nematodes in flooded ecosystems. Indian Journal of Agricultural Sciences, 91(5), 712–718. [Google Scholar] [Crossref]

13. Singh, S., Yadav, R. & Pandey, R. (2022). Status of plant-parasitic nematodes in major rice-growing regions of India. Annals of Plant Protection Sciences, 30(2), 215–221. [Google Scholar] [Crossref]

14. Verstraeten, B., Atighi, M. R., Ruiz-Ferrer, V., Escobar, C., De Meyer, T., & Kyndt, T. (2021). Non-coding RNAs in rice–nematode interaction. BMC Genomics, 22, 560. [Google Scholar] [Crossref]

15. Waghmare, C. D., Pankaj, P., & Pervez, R. (2024). Integrated management of rice root-knot nematode using bioagents and botanicals. Indian Journal of Agricultural Sciences, 95(10). [Google Scholar] [Crossref]

16. Yadav, R.K., Kumar, M. & Singh, B. (2023). Survey of weed hosts associated with rice root-knot nematode in northern India. Indian Journal of Weed Science, 55(3), 276–281. [Google Scholar] [Crossref]

• Nest-Building Behaviour in Ants: Structural Adaptations and Environmental Interactions
• Diversity of Spiders and Seasonal Variation Surrounding “Madosilli Waterfall” Sarangarh-Bilaigarh District, Chhattisgarh, India.
• Assessment of Lipid Peroxidation in Liver and Heart Of D-Galagctose Induced Chick Embryo
• Avian Diversity in and Around Nazare Dam, Jejuri, Pune District, Maharashtra, India
• Integrative Morphological and Molecular Classification of Culex vishnui Larvae from Diverse Ecological Habitats of Uttar Pradesh