Indexing

Prevalence of Alternaria Leaf Blight of Broad Bean in the Valley Districts of Manipur

Author: Rimamay Konjengbam, L.N.K. Singh, Ph. Sobita Devi, B. Sinha, K.I. Singh and N. Gopimohan Singh

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Abstract

Alternaria leaf blight of broad bean is one of the significant fungal diseases of broad bean in Manipur. The disease initiates from the older plant parts, spreads to the younger parts and eventually the entire plants are affected. The affected plant becomes completely blighted. The disease is predominantly distributed in the valley districts of Manipur. The disease incidence and severity varied among all the selected locations of the districts in study. The disease incidence ranges between 29.67% to 59.67% during 2020-2021 and 49.00% to 84.00% during 2021-2022. The disease severity ranges between 19.11% and 51.78% during 2020-2021 and 26.15% and 62.96% during 2021-2022. The disease incidence and severity in all the surveyed areas were lowest in December and highest in February. All the fungal isolates collected from the surveyed areas produced a typical disease lesion in pathogenicity tests on broad bean plants and detached broad bean leaves. The extent of pathogenicity on both the plants and detached leaves varies for all the fungal isolates. The presence of concentric rings on the leave lesion is the most conspicuous symptom of this disease. As the disease progressed, the plant becomes blighted and dried.

Keywords

Broad bean, Alternaria alternata, blight, concentric rings, incidence, severity, pathogenicity

Conclusion

Alternaria leaf blight of broad bean is widely distributed in the valley districts of Manipur. The disease exceptionally affects the eatable portions namely, broad bean pods, seeds and leaves. The disease remarkably reduces yield and quality of the produce thereby causing notable economic losses. The disease is distinguishable by the presence of characteristics target board or concentric rings on the leave lesions. In the later stage the entire plants becomes wilted and completely dried up. The frequency of this disease varied among all the five valley districts of Manipur.

References

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How to cite this article

Rimamay Konjengbam, L.N.K. Singh, Ph. Sobita Devi, B. Sinha, K.I. Singh and N. Gopimohan Singh (2023). Prevalence of Alternaria Leaf Blight of Broad Bean in the Valley Districts of Manipur. Biological Forum – An International Journal, 15(3): 59-71.