Integrated management of wet root rot, yellow mosaic, and leaf crinkle diseases of urdbean by seed treatment and foliar spray of insecticide, fungicide, and biocontrol agent

Abstract

Various seed treatment combinations comprising insecticide, fungicide, and a biocontrol agent along with foliar sprays of insecticides were evaluated for the management of leaf crinkle (Urdbean leaf crinkle virus [ULCV]), yellow mosaic (Mungbean yellow mosaic virus [MYMV]), and wet root rot (WRR; Rhizoctonia solani) diseases of urdbean (Vigna mungo) under field conditions. Seed treatment with a combination of imidacloprid, carboxin + tetramethylthiuram disulfide (TMTD), and Pusa 5SD (Trichoderma virens) provided the highest seed germination (77.5%) and grain yield (953.3 kg/ha) with the lowest WRR (3.7%), mungbean yellow mosaic (MYM, 17.2%), urdbean leaf crinkle (ULC, 12.1%) diseases, and whitefly population (13.5–6.7 per plant). Among foliar sprays, the first spray of imidacloprid at 30 days after sowing (DAS) followed by the second spray of spinosad at 45 DAS showed less disease development (10.6% MYM and 7.5% ULC diseases) and whitefly populations (21.2–2.1 per plant) with the highest grain yield (1035.4 kg/ha). Among the interactions of seed treatment and foliar spray, a combination of seed treatment with imidacloprid, carboxin + TMTD, and Pusa 5SD (T. virens) and foliar sprays of imidacloprid and spinosad at 30 and 45 DAS, respectively, provided the lowest incidence of all three diseases (2.9% WRR, 7.0% yellow mosaic, and 4.2% leaf crinkle diseases) and whitefly populations (11.7–1.0 per plant) along with the highest grain yield (1258.6 kg/ha). Identical seed treatments may be combined with foliar sprays of dimethoate and spinosad at 30 and 45 DAS, respectively. These seed treatments and foliar sprays individually and in combinations reduced the whitefly populations responsible for the spread of the viral diseases.