Evaluating the efficacy of chemical, botanical, and cow urine-based interventions for sustainable management of major lentil diseases
Abstract
Lentil is one of Bangladesh’s most significant pulse crops, but fungal diseases, especially Stemphylium blight caused by Stemphylium botryosum, severely limit its productivity. The current study was conducted at the Regional Agricultural Research Station (RARS), Jashore, to assess the efficacy of selected fungicides, botanical extracts, and cow urine in managing major lentil diseases and improving yield performance. The experiment used BARI Masur-6 in a Randomized Complete Block Design with three replications during three consecutive rabi seasons (2013–14, 2014–15, and 2015–16). Treatments included cow urine (5%); garlic, datura, mahogany leaf and seed, neem, and fern leaf extracts (5% solutions); fungicides such as Dithane M-45, Bavistin, Cupravit, Ridomil Gold, and Rovral; and an untreated control. Yield and yield-contributing characters were recorded, and disease severity was measured using the Percent Disease Index (PDI). The findings showed that seedling mortality was mainly linked to soil-borne infections and declined with increasing plant age. Higher temperatures and humidity promoted disease development, as indicated by positive linear associations between PDI and maximum and minimum temperatures, as well as relative humidity. Across years, Rovral 50WP consistently outperformed all treatments in reducing disease severity and improving yield quality. Rovral-treated plots produced the highest stover production and grain yield (2.79, 2.07, and 2.13 t ha⁻¹ in the corresponding years), followed by Ridomil Gold, Dithane M-45, fern leaf extract, and cow urine. Compared with fungicides, botanical extracts and cow urine showed moderate efficacy but performed better than the untreated control, which consistently yielded the lowest. The results indicate that Rovral 50WP is highly effective against Stemphylium blight and improves lentil yield, while cow urine and some botanical extracts have potential as environmentally acceptable alternatives for integrated disease management. Res. Agric. Livest. Fish. 13(2): 263-274