Management of Cercospora leaf spot (Cercospora abelmoschi Ellis and Everh.) of okra [Abelmoschus esculentus (L.) Moench] by botanicals and chemical fungicides

Abstract

Okra, also known as gumbo or ladies' fingers, botanically known as [Abelmoschus esculentus (L.) Moench] is one of the most popular and widely grown vegetable crops throughout the world and treated as “protective food” universally. Diseases play a vital role in yield losses of the crop. Among them, fungi are one of the most important and prevalent pathogens which attack the crops from seedling to harvesting stage. Among the fungal diseases Cercospora leaf spot of okra incited by Cercospora is one of the most economically important in all regions wherever okra is grown. Therefore, research was carried out in the Kharif seasons of 2023–24 at the Research Farm, Department of Plant Pathology at the Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, U.P. The botanicals and fungicides were applied in field. The experiment was laid out in RBD (Randomized block design) with 3 replications. Treatments were applied after the appearance of the disease symptoms in the three sprays at the interval of 15 days. Treatments comprised of T0 (Control); T1 {Carbendazim (1g/kg) - ST+ FS (0.1%)}; T2 {(Tebuconazole 50%+ Trifloxystrobin 25% w/w WG (0.05%) – FS}; T3 {(Carbendazim 12% + Mancozeb 63% WP)-FS (0.02%)}; T4{Mancozeb 75% WP (0.2%) - FS}; T5 {Neem leaf extracts @ 10% - FS}; T6 {Garlic clove extract @ 10% - FS} and T7 {Eucalyptus leaf extract @ 10% - FS}. Among the different treatments applied at 45 DAS, T2 {(Tebuconazole 50%+ Trifloxystrobin 25% w/w WG (0.05%) – FS} showed minimum per cent of disease intensity (PDI) (5.56%); at 60 DAS, minimum per cent of disease intensity (PDI) (12.42%) and at 75 DAS, minimum percent of disease intensity (PDI) (17.66%). T2 {(Tebuconazole 50%+ Trifloxystrobin 25% w/w WG (0.05%) – FS} showed maximum fruit yield per hectare (12.95 t/ha) and highest cost benefit ratio (1:2.80). Hence, T2 {Tebuconazole 50%+ Trifloxystrobin 25% w/w WG (0.05%) – FS} proved to be the most effective treatment against Cercospora leaf spot of Okra compared to other treatments and the untreated control. However, since this investigation was conducted during a single crop season (Kharif) and under the specific climatic conditions of Prayagraj (U.P.), further trials are necessary to validate these results for broader recommendations.