Characterization of Pod Rot Fungus of Blackgram and its Management using Fungicides and Bioagents for Enhancing Seed Germination and Vigour

Author: P. Kishore Varma, B. Shiva, N. Kamakshi, M.V. Ramana, V. Vasanthi, A. Janaki Prasad, Bavana Keerthi, Pushpa Rajyam and Sharon Roj

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Abstract

Pod rot is one of the major causes for deterioration of blackgram seed during untimely rains at harvest. Studies on blackgram pod rot at RARS, Lam, Guntur during Kharif 2022 revealed that Fusarium sp. is the major culprit for pod deterioration that results in low seed germination. The major pod rot fungus was characterized as Fusarium chlamydosporum using ITS primers. An attempt has been made in this study to evaluate various fungicides and biocontrol agents as seed treatment to enhance seed germination and vigour of pod rot affected seed. Eight fungicides and biocontrol agents were tested in vitro for their Fusarium suppressing and seed growth promoting ability using poisoned food, dual culture and roll paper towel methods. Among different fungicides tested at 500 ppm and 1000 ppm concentrations, tebuconazole, hexaconazole, carbendazim, carbendazim + mancozeb, propiconazole showed 100 per cent inhibition of mycelial growth of Fusarium sp. In case of bioagents, Pseudomonas aeruginosa P20 showed highest mycelial growth inhibition (88.24%) followed by Pseudomonas chlororaphis P19 (87.65%), Bacillus vallismortis B20 (77.65%) and Bacillus inaquosorumB2 (74.12%) in dual culture assay. Seed treatment with fungicides and bioagents followed by roll towel paper method of seed germination revealed improvement of seed germination and other growth parameters besides reducing seed borne fungal infection when compared to control. Highest germination and seedling vigour were obtained in Bacillus inaquosorum treated blackgram seeds when compared to all other treatments. Though, germination and seed infestation were found to be enhanced in most of the chemical treatments, some of the fungicide formulations used were found inhibitory to radicle and plumule growth. Overall, the study indicated that the germination of pod rot affected blackgram seeds could be improved by seed treatment with fungicides and biocontrol agents.

Keywords

Urdbean, Vigna mungo, pod rot, seed germination, seedling vigour, fungicides, bioagents

Conclusion

Overall, the results of the present study revealed the association of Fusarium chlamydosporum with the pod rot of blackgram in Guntur district of Andhra Pradesh during Kharif, 2022. Bacterial bioagents and triazole compounds were found inhibitory to the mycelial growth of F. chlamydosporum under laboratory conditions compared to other bioagents and other group of fungicides studied. Seed treatment with Bacillus inaquosorum could be advocated to reduce seed infection of pod rot fungus of blackgram thereby improving seed germination and seedling vigour. In future, the effective treatments have to be assessed as pre-harvest sprays in vivo to reduce the incidence of pod mycoflora that affect the blackgram seed germination.

References

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How to cite this article

P. Kishore Varma, B. Shiva, N. Kamakshi, M.V. Ramana, V. Vasanthi, A. Janaki Prasad, Bavana Keerthi, Pushpa Rajyam and Sharon Roj (2023). Characterization of Pod Rot Fungus of Blackgram and its Management using Fungicides and Bioagents for Enhancing Seed Germination and Vigour. Biological Forum – An International Journal, 15(9): 61-67.