Impact of different fungicides against black spot disease caused by (Marssonina rosae) under Punjab conditions

Abstract

Black spot is one of the most devastating and widespread disease in rose plants. Efficacy of seven fungicides were evaluated against this disease caused by Marssonina rosae (Lib.) Lind at Research farm, Department of Floriculture and Landscaping, Punjab Agriculture University, Ludhiana during 2022-2024. The Percent disease index (PDI) ranged from 17.11 to 45.15, 15.23to 38.22 and 19.89 to 50.25 percent in 2022, 2023 and 2024 respectively. The pooled data results indicated Tebuconazole 50% + Trifloxystrobin 25% WG (17.41%) followed by Chlorothalonil 75% WP (19.94) and Azoxystrobin 23% SC (22.58%) were found highly effective in controlling the disease. Highest PDI was obtained in plants treated with Metiram 75% WP (44.54%) with a disease control of (23.71 percent). Maximum Yield and no of flowers per plant were observed in Tebuconazole 50% + Trifloxystrobin 25% WG followed by Difenoconazole 25% EC and minimum in Captan 50% WP and Metiram 75% WP in all the three years. However, all the treatments were found significantly superior than untreated control.