Alternaria Blight – A Serious Affliction of Rapeseed Mustard: A Review

Author: Mithilesh Kumar Pandey, Malik M. Ahmad, Saba Siddiqui, Akshay Kumar and Sandeep Kumar Singh

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Abstract

Rapeseed mustard is an important oilseed crop which dominates the world of oilseed after the soybean. Alternaria blight is the global headache of crop scientists, it can reduce yield by up to 70%. Currently, 50% of rapeseed yield is lost due to Alternaria blight around the globe. This disease is mainly caused by two fungal organisms- Alternaria brassicae and Alternaria brassicicola. These infections don't have reproductive stages and live as conidia or conidiospores on the remains of previous crops and vulnerable weeds. These are necrotrophic pathogens. The illness initially manifests as a black spot but subsequently grows larger and transforms into noticeable spherical patches with concentric rings. Many spots coalesce to form large patches showing blight and cause defoliation in severe cases, in the stem and pod areas circular to linear lesions may be found which elongate later. Small, discoloured, and shrivelled seeds are produced by infected pods. Reduced photosynthetic potential, early defoliation, flower bud abortion, premature ripening, siliquae dehiscence, seed shrivelling and reduced seed size, impairs seed colour, and reduced oil content are some of the factors that contribute to this disease's significant yield losses. In this review, we’ll discuss the Alternaria blight taxonomy, economic importance, habitat, host range, pathogenicity, survival, symptoms and management. It would be helpful to find the impact of Alternaria disease on the mustard crops.

Keywords

Rapeseed-mustard, Alternaria blight, symptoms, pathogenicity, management, breeding

Conclusion

Pathogenic Alternaria species are global and severe, making Alternaria leaf blight the most destructive disease of oilseed brassicas worldwide. Alteraria blight reduces the quality and quantity of oilseed brassica harvests, and no resistant crop species have been found. However, coenospecies (wild species) of Brassicas such B. desnottesi, C. sativa, C. pseuderucastrum, D. berthauti, D. catholica, D. cretacea, D. erucoides, and E. gallicum were entirely resistant to A. brassica. Other techniques might handle Alternaria leaf blight as grown Brassicas lack resilience. Fungicides are widely utilised. Despite their widespread usage against infections, fungicides pose substantial health risks and pollute the environment. Thus, moderately resistant cultivars, plant and natural products, bio-control agents, and agronomic changes are increasingly prioritised for disease management since they are more cost-effective, eco-friendly, and safe.

References

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How to cite this article

Mithilesh Kumar Pandey, Malik M. Ahmad, Saba Siddiqui and Akshay Kumar (2023). Alternaria Blight – A Serious Affliction of Rapeseed Mustard: A Review. Biological Forum – An International Journal, 15(2): 436-443.