Evaluation of fungicides and bacterial antagonists for management of Corynespora leaf spot on mungbean (Vigna radiata L. Wilczek)

Authors: BAIRWA, NARENDRA - Central Agricultural University; JAMBHULKARV, PRASHANT - Central Agricultural University; SUSHMITA, VENKATESH - Central Agricultural University; MEENAKSHI, ARYA - Central Agricultural University; MANJUNATHA, NANJUNADAPPA - Indian Council Of Agricultural Research (ICAR); BAJPAI, RUCHIRA - Central Agricultural University; SINGH, DINESH - Indian Council Of Agricultural Research (ICAR); MANI, CHANDRA - Indian Agricultural Research Institute; KUMAR, SHAILENDRA - Central Agricultural Research Center; CHATURVEDI, SUSHIL - Central Agricultural University; Lakshman, Dilip

Submitted to: Archives of Phytopathology and Plant Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2022
Publication Date: 1/25/2022
Citation: Bairwa, N.K., Jambhulkarv, P.P., Sushmita, V., Meenakshi, A., Manjunatha, N., Bajpai, R., Singh, D., Mani, C., Kumar, S., Chaturvedi, S.K., Lakshman, D.K. 2022. Evaluation of fungicides and bacterial antagonists for management of Corynespora leaf spot on mungbean (Vigna radiata L. Wilczek). Archives of Phytopathology and Plant Protection. 55:433-453. https://doi.org/10.1080/03235408.2022.2025686.
DOI: https://doi.org/10.1080/03235408.2022.2025686

Interpretive Summary: Corynespora leaf spot caused by the fungus C. cassiicola is a worldwide major disease of bean, causing yield loss of bean and foliage. To minimize losses of mungbean (Vigna radiate L. Wilczek) due to this disease, talc-based formulations of bacterial antagonists, including Bacillus subtilis DTBS-5, B. amyloliquefaciens DSBA-11, and Pseudomonas fluorescens DTPF-3, two systemic fungicides (Carbendazim 50 WP and Azoxystrobin 23 SC) and three contact fungicides (Propineb 70 WP, Mancozeb 75 WP, and Copper oxychloride 50 WP) were individually evaluated in vitro and in field. In the field experiments conducted during Kharif season of 2019 and 2020, two sprays with Azoxystrobin 23 SC@ 0.5 ml lit-1 were most effective in both seasons to reduce disease severity by 57.7% and 67.7%, respectively. Treatment with Azoxystrobin 23 SC also resulted in a maximum increase of 281.5 Kg ha-1 in grain yield, followed by treatments with P. fluorescens DTPF-3 (264.7 Kg ha-1 yield increase), and B. subtilis DTBS-5 (264.7 Kg ha-1 yield increase). The inferences made from those experiments will be highly useful for better management of Corynespora leaf spot of Mungbean in India and elsewhere. The information gathered will also be helpful to plant pathologists, extension workers, and farmers.

Technical Abstract: To minimize losses due to Corynespora leaf spot, systemic and contact fungicides and formulation of bacterial antagonists like Bacillus subtilis DTBS-5, B. amyloliquefaciens DSBA-11, and Pseudomonas fluorescens DTPF-3 talc-based formulations were evaluated to manage the disease. Though mancozeb has the lowest EC50 value of 1250.54 ppm it was not efficient in the field experiment. In addition, dual culture assay to determine the efficacy of bacterial antagonists against C. cassiicola, B. amyloliquefaciens DSBA-11 effectiovely reduced growth of C. cassiicola. In the field experiments conducted during Kharif 2019 and 2020, two sprays with Azoxystrobin 23 SC@ 0.5 ml lit-1 were found most effective in reducing disease severity by 57.7% and 67.7% respectively during Kharif 2019 and 2020. Azoxystrobin 23 SC treatment resulted in a maximum increase of 281.5 kg in grain yield followed by Pseudomonas fluorescens DTPF-3 264.7 kg and Bacillus subtilis DTBS-5 248.9 kg yield.