Field management of Corynespora cassiicola in cotton under close spacings

A field trial was conducted to evaluate the efficacy of different fungicides against Corynespora leaf spot in variety, LHDP Cotton - 5 at Regional Agricultural Research Station, Lam, Guntur during Kharif 2021-22 in a split-plot design with four main plots viz., 75 cm x 30 cm; 75 cm x 45 cm; 60 cm x 30 cm and 60 cm x 45 cm; and six subplots viz., T1-Hexaconazole@ 0.2%; T2-Carbendazim @ 0.1%; T3- Propiconazole @ 0.1%; T4-Metiram + pyraclostrobin@ 0.3%; T5-Fluxapyroxad + pyraclostrobin @ 0.06% and T6-Untreated Control and replicated twice. Three sprays were given at 15 days interval with the first spray initiated as soon as the disease was observed. Disease was scored by adopting a standard scale of 0 to 4 in ten plants tagged randomly. Significant difference was found among different fungicides tested over all spacings, however interaction effect was non significant. Least area under disease progress curve (413.91) was observed with fluxapyroxad + pyraclostrobin @ 0.06%indicating maximum efficacy of fluxapyroxad + pyraclostrobin @ 0.06% in controlling cotton Corynespora leaf spot. Highest reduction of disease (58.2%) and highest yield (30.20 q/ha) were recorded with fluxapyroxad + pyraclostrobin @ 0.06%. Highest benefit: cost ratio of 3.0 was obtained with propiconazole @ 0.1% followed by fluxapyroxad + pyraclostrobin @ 0.06% (2.95).