Optimising Organic Fertiliser Application to Enhance Photosynthetic Pigments and Physiological Performance in Moringa oleifera Seedlings

Abstract

In Malaysia, sustainable agricultural practices characterised by organic production systems are gaining increasing recognition because of their potential to reduce dependence on synthetic inputs. Moringa oleifera is a highly nutritious perennial species with well-documented medicinal and agro-ecological benefits. Chicken manure compost, characterised by its high nutrient content, gradual nutrient release and contribution to soil organic matter, has been recognised as an effective and environmentally sustainable fertiliser. This study evaluated the effect of chicken manure compost application on photosynthetic pigment composition in M. oleifera seedlings. The experiment was conducted using a randomised complete block design (RCBD) comprising four fertiliser rates (0, 100, 200 and 300 g plant⁻¹) with four replications. Under nursery conditions, photosynthetic pigment parameters were measured, including relative chlorophyll content, chlorophyll a, chlorophyll b, total chlorophyll and carotenoid concentration. Analysis of variance (ANOVA) indicated significant treatment effects (p < 0.05) for all pigment parameters, with particularly strong responses observed for total chlorophyll content and chlorophyll a (p < 0.01). Post hoc mean separation showed that fertiliser-treated plants consistently exhibited higher pigment concentrations than the unfertilised control, with increases of up to approximately 22% in relative chlorophyll content, 34% in chlorophyll a and 33% in total chlorophyll. Pigment accumulation increased markedly up to 200 g plant⁻¹, followed by stabilisation, indicating a saturating response rather than a continuous increase at higher application rates. Quadratic regression analysis further confirmed a positive but non-linear relationship between fertiliser application rate and pigment accumulation. These findings demonstrate that chicken manure compost enhances chlorophyll biosynthesis and carotenoid accumulation in M. oleifera seedlings, reflecting improved photosynthetic capacity and physiological vigour. Overall, this study highlights the effectiveness of organic nutrient inputs in promoting early seedling development and provides practical guidance for sustainable Moringa oleifera cultivation.