Evaluating the Impact of Fertilisers and Elicitors on Amaranthus cruentus (L): Sustainable Fertilization and Elicitation Strategies for Enhanced Nutrition and Productivity

Abstract

Amaranthus cruentus is a leafy vegetable that is widely grown and consumed in Nigeria. However, little effort has been made to focus on sustainable fertilization and enhance its micronutrient content. Addressing this issue could help alleviate micronutrient deficiencies in Nigeria. In 2018, Amaranthus cruentus plants were grown in the screen house at the Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria to assess the impact of fertilisers and elicitors on the growth, yield, and micronutrient composition of Amaranthus cruentus. The experiment comprised of compost manure (CP) applied at the rates of 5, 10, and 15 t/ha (CP5, CP10, and CP15), poultry manure (PM) applied at equivalent rates (PM5, PM10, and PM15), and NPK 15:15:15 fertiliser applied at the rates of 50, 100, and 150 kg/ha (NPK50, NPK100, and NPK150), Methyl jasmonate and Salicylic acids applied each at 125, 250, 500 µmol/L (MejA125, MejA250, MejA500; SA125, SA250, SA500,) with a control group receiving no treatment. The study used a completely randomized design with three replicates. Data were collected on plant height, number of leaves, leaf area, and stem girth. Harvesting was done six weeks after sowing, and fresh weight, dry matter was determined. Folate, iron, zinc, moisture, crude fiber, and ash contents were determined. Data were analysed with analysis of variance (ANOVA). Means were separated with Duncan Multiple Range Test (P=0.05). Amaranthus cruentus plants treated with NPK100 exhibited the highest plant height and leaf area. PM10 treatment yielded the highest marketable yield (52.29 g/plant). SA250 resulted in significantly higher folate content (250.20 µg/100) compared to the control. CP10 treatment led to higher iron content (22.00 mg/100g) and zinc concentration (3.86 mg/100g). Compost and poultry manure fertilisers at a rate of 10 t/ha and salicylic acid at 250 µmol/L can improve the nutritional quality of Amaranthus cruentus.