MANAGEMENT OF ALTERNARIA LEAF SPOT OF CABBAGE THROUGH SELECTED FUNGICIDES, SPENT MUSHROOM SUBSTRATE AND THEIR COMBINATION

Abstract

An field experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University for the management of Alternaria leaf spot of cabbage (Brassica oleraceae) through the combination of spent mushroom substrate and some selected fungicides during Rabi season (November, 2021 to March, 2022). The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The experimental treatments were T 0 : Control (No treatment); T 1 : Spent mushroom substrate (SMS) @ 15 t ha -1 ; T 2 : Rovral 50 WP @ 2.0 ml/L of water; T 3 : Kurenox 50 WG @ 2.5 g/L of water; T 4 : Knowin 50 WP @ 20 g/L of water; T 5 : Mancer 75 WP @ 2g/L of water; T 6 : Spent mushroom substrate @ 15 t ha -1 + Rovral 50 WP @ 2.0 ml/L of water; T 7 : Spent mushroom substrate @ 15 t ha -1 + Mancer 75 WP @ 2g/L of water; T 8 : Spent mushroom substrate @ 15 t ha -1 + Kurenox 50 WG @ 2.5 g/L of water; T 9 : Spent mushroom substrate @ 15 t ha -1 + Knowin 50 WP @ 20 g/L of water. Treatment T 6 combined with soil amendment with spent mushroom substate followed by spraying with Rovral 50 wp (0.2%) at 7 days interval showed the best performances reducing leaf infection, plant infection head infection by 52.19 %, 47.49% and 100% respectively while the leaf infection, plant infection head infection respectively were 33.86%, 48.66% and 0.0% respectively. Treatment severity of plant by 35.97% while the severity index was recorded 19.94%. Treatment yielded the highest plant height (21.79cm), diameter of cabbage head (21.38 cm), weight of cabbage head (2.26kg plant) increasing the cabbage yield by 58.34% over control. As per the performances of the treatments against the disease, the efficacy were ranked as control ( T 0).

T 6< T 9< T 2< T 8< T 4< T 6 reduces the T 3< T 6 also T 5< T 1 as