Influence of Organic Fertiliser Management on Growth, Yield Performance, and Quercetin Content of Four Onion (Allium cepa L.) Cultivars under Highland Agroecological Conditions of Cameroon
Abstract
The productivity and nutritional quality of onion (Allium cepa L.) are influenced by cultivar characteristics and nutrient management practices. However, limited information exists on the interaction between onion cultivars and organic fertiliser sources in determining yield performance and quercetin accumulation under highland agroecological conditions of Cameroon. This study evaluated the influence of organic fertiliser management on growth, yield and quercetin content of four onion cultivars grown in Bambili, North-West Region of Cameroon. The experiment was conducted using a 4 × 3 factorial arrangement in a Randomised Complete Block Design (RCBD) with three replications. Four cultivars (Red Bombay, Red Creole, Texas Grano and Pusa White Flat) were evaluated under three fertiliser treatments: cow dung, fowl droppings and an unfertilised control. Data on stem diameter, plant height, number of leaves, bulb yield and quercetin content were analysed using analysis of variance (ANOVA), and treatment means were separated using Tukey’s HSD test at 5% probability. Cultivar, fertiliser treatment and their interaction significantly influenced growth, yield and quercetin content. Organic fertiliser application improved vegetative growth and bulb yield compared with the control, with fowl droppings producing the best overall response. Red Bombay showed superior performance, recording the highest stem diameter (10.79 mm), plant height (58.32 cm), bulb yield (129.96 g plant⁻¹) and quercetin content (31.30 mg plant⁻¹). The highest yield (158.63 g plant⁻¹) and quercetin concentration (33.37 mg plant⁻¹) were obtained from Red Bombay treated with fowl droppings. The study demonstrates that integrating suitable cultivar selection with organic fertiliser management can improve onion productivity and nutritional quality under highland conditions of Cameroon.