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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #409127
Research Project: Detection, Biology, and Genomics of New and Emerging Viral and Bacterial Diseases of Ornamental Plants

Location: Floral and Nursery Plants Research

Title: Cowpea leaf and pod spots caused by Periconia igniaria and their potential control by biosynthesized zinc oxide nanoparticles

Author
item ABDED-SAMAD, FATEN - Minia University
item Huang, Qi
item ABDEL-LATIF, MARTOUK - Minia University
item SHEHATA, ZEKRY - Minia University
item ARMANYOUS, HANAA - Minia University
item AHMAD, ABDELMONIM - Minia University

Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2024
Publication Date: 8/12/2024
Citation: Abded-Samad, F.H., Huang, Q., Abdel-Latif, M.R., Shehata, Z.A., Armanyous, H.H., Ahmad, A.A. 2024. Cowpea leaf and pod spots caused by Periconia igniaria and their potential control by biosynthesized zinc oxide nanoparticles. Journal of Plant Pathology. https://doi.org/10.1007/s42161-024-01714-z.
DOI: https://doi.org/10.1007/s42161-024-01714-z

Interpretive Summary: Cowpea is an economically important legume crop widely cultivated around the world on an estimated 14.5 million ha of land with a total annual production of approximately 6.5 million metric tons. Cowpea is subject to attacks by a wide range of plant pathogenic bacteria, fungi, viruses, and nematodes with severe impact on crop production. Scientists in Egypt, in collaboration with an ARS scientist, surveyed the main cowpea growing regions in El-Minya, Egypt for cowpea leaf and pot spot disease and identified the causal agent to be a fungal pathogen. To control the disease, they synthesized zinc oxide nanoparticles biologically by using green coffee extract. They found that the nanoparticles effectively reduced fungal growth, and significantly reduced leaf and pod spot disease on detached cowpea leaves and pods, as well as in cowpea plants. This study demonstrated that biosynthesized zinc oxide nanoparticles have great potential to be developed into an effective and eco-friendly control method against cowpea leaf and pod spot disease.

Technical Abstract: Cowpea is subject to attacks by a wide range of dangerous plant pathogens including bacteria, fungi, viruses, and nematodes. In this study, a field survey was conducted in main cowpea growing regions of El-Minya Governorate of Egypt including Minya, Beni Mazar and Maghagha districts for leaf and pod spot disease. Our results revealed that leaf and pod spot disease of cowpea was present in all surveyed fields with the highest disease incidence and severity found in Minya District. The causal agent of the disease was determined to be Periconia igniaria based on morphology of the fungal isolates, internal transcribed spacer sequence homology to a P. igniaria strain, as well as fulfillment of Koch’s postulates. To explore control measures, zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles (NPs) were synthesized biologically using green coffee extract. Both NPs were characterized, and their formulations confirmed using scanning electron microscopy and the energy spectrum dispersion analysis. The biosynthesized ZnO- and MgO-NPs were demonstrated to have antifungal activity against in vitro mycelium growth of P. igniaria at all tested concentrations from 25 to 200 ppm, and ZnO NPs were more effective than MgO NPs at the same concentration. When 100 ppm of ZnO NPs was tested in planta, it significantly reduced disease incidence and severity of leaf and pot spots in detached cowpea leaves and pods under laboratory conditions, and in cowpea plants under greenhouse conditions. Our results demonstrated that the biosynthesized ZnO NPs have great potential to be developed into an effective and eco-friendly control method against cowpea leaf and pod spot disease caused by P. igniaria.