ASSESSING THE IMPACT OF ORGANIC FERTILIZER ON THE GROWTH AND YIELD OF OCIMUM GRATISSIMUM

ABSTRACT This study investigated the impact of organic manure, specifically cow dung, on the growth and yield parameters of Ocimum gratissimum (Scent leaf), a medicinal plant widely used in urban and peri-urban agriculture in Benin. The research was conducted over four weeks at the biological garden of Kaduna Polytechnic, Nigeria, employing a Completely Randomized Design (CRD) with three treatments: Treatment 1 (T1) and Treatment 2 (T2) both supplemented with cow dung, and a control group without manure. The growth parameters assessed included plant height, number of leaves, and leaf area. The results demonstrated that cow dung significantly enhanced the vegetative growth of Ocimum gratissimum. Plants in T1 exhibited the most substantial growth, with heights increasing from 4 cm to 26 cm, leaf counts from 2 to 36, and leaf areas expanding from 0.4 cm² to 5.08 cm². In contrast, T2 showed slightly less growth, while the control group demonstrated considerably lower growth rates across all measured parameters. Statistical analysis through ANOVA confirmed significant differences (p < 0.001) among the treatments for all growth metrics, underscoring the effectiveness of cow dung in promoting growth. This study not only confirms the role of organic manure in sustainable agriculture but also highlights its potential for enhancing the yield and quality of medicinal plants like Ocimum gratissimum. Recommendations include further investigation into optimal application rates and long-term effects on soil health, plant quality, and essential oil production.