Characterization and sustainable management of vector-borne viral pathogens in okra (Abelmoschus esculentus L.)

Abstract

Okra (Abelmoschus esculentus L.) is a significant vegetable crop in India, but its cultivation is severely impacted by viral diseases, particularly okra yellow vein mosaic disease (OYVMD).This study was conducted to evaluate the effectiveness of various pest management modules against whiteflies (Bemisia tabaci), the primary vector of OYVMD, and to assess the incidence and severity of OYVMD in okra. The experiment was carried out at the Central Research Station of Odisha University of Agriculture and Technology during the kharif seasons of 2019 and 2020, using a Randomized Complete Block Design (RCBD) with five replications. Four treatments were evaluated: an Integrated Module, a Biointensive Module, a Chemical Module, and an Untreated Control. The results demonstrated that both the Integrated and Chemical modules significantly reduced the whitefly population and managed it effectively throughout the cropping period, with mean populations of 2.19 whiteflies per leaf. These modules also effectively suppressed the incidence and severity of OYVMD with the highest incidence being recorded in bio-intensive module. Molecular characterization of both yellow vein mosaic virus and whiteflies collected from virus infected plants were also done by conducting PCR followed by gel electrophoresis of isolated DNA samples which revealed that the whiteflies from Bhubaneswar grouped phylogenetically with the whitefly isolates from Indonesia, Thailand and China. In case of viruses, okra enation leaf curl virus from Bhubaneswar clustered with Mungbean yellow mosaic virus (MYMV) from Raichur and Hyderabad.