YIELD LOSS ASSESSMENT FOR GREY BLIGHT OF MUSTARD CAUSED BY Alternaria spp.

Abstract

A pot experiment was carried out during the period from December 2021 to March 2022 to assess the yield loss of mustard due to grey blight disease. The experiment consists of twelve treatments viz, T 0 ii

= Control (Field spraying with plain water); T 1 = One field spraying with Rovral 50 WP @ 0.2%; T 2 = Two field spraying with Rovral 50 WP @ 0.2%; T 3 = Three field spraying with Rovral 50 WP @ 0.2%; T 4 = Four field spraying with Rovral 50 WP @ 0.2%; T 5 = Five field spraying with Rovral 50 WP @ 0.2%; T 6 = Six field spraying with Rovral 50 WP @ 0.2%; T 7 = Seven field spraying with Rovral 50 WP @ 0.2%; T 8 = Eight field spraying with Rovral 50 WP @ 0.2%; T 9 = Nine field spraying with Rovral 50 WP @ 0.2%; T 10 = Ten field spraying with Rovral 50 WP @ 0.2% and T 11 = Eleven field spraying with Rovral 50 WP @ 0.2%.. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Different treatments comprising different number of sprayings had remarkable effect on the disease incidence and severity of grey blight, yield and yield contributing characters of mustard. The lowest (0.0%) percent disease index (PDI) and the highest yield (934.3 kg/ha) was recorded in case of treatment T 11 where eleven foliar spraying were applied with Rovral 50 WP @ 0.2% at 7 days interval. The highest PDI (84%) and the lowest yield (357.6 kg/ha) was counted in case of treatment T 0 (control). The disease severity (PDI) and yield were varied in case of other treatments on the basis of number of fungicide spraying. Using the varied disease severity (PDI) and corresponding yield, the mathematical yield loss assessment model was constructed as Y = 0.50 + 2.32Xi using the regression equation.