Influence of exogenously applied k-carrageenan at various concentrations on plant growth, phytochemical content, macronutrients, and essential oils of Ocimum basilicum

Food safety and security are now among the most urgent problems to be resolved as the world's population continues to grow. Intensive agriculture is required to meet the demands of a growing population and guarantee greater agricultural yield. Chemical pesticides and fertilizers are an essential part of intensive farming. Their extensive use accelerates the depletion of other important and minor nutrients, resulting in poor soil fertility and nutritional imbalance. There are serious health and environmental hazards associated with several of these hazardous agricultural chemicals. In context, for the first time, this study represents an innovative experiment exploring the impact of exogenously applied k-carrageenan on plant growth, physiological parameters, phytochemical content, macronutrients, and essential oil percentage in Ocimum basilicum plants. The investigation assessed the effect of varying k-carrageenan levels; 0.30, 0.60, 0.90, and 1.20 mM versus untreated control. The findings revealed that all k-carrageenan treatments significantly enhanced growth indicators compared to the control. The phytochemical analysis demonstrated that foliar application of k-carrageenan, particularly at 1.20 mM, significantly enhanced total chlorophyll, chlorophyll a, chlorophyll b, and total carbohydrate and essential oil percentage compared to the untreated control. O. basilicum essential oils show rich, nuanced flavors with higher levels of Methyl cinnamate, Camphor, trans-methyl cinnamate, Eucalyptol, Linalool, and β-Caryophyllene among treatments. Treatment effects were also observed in the macroelements content of Nitrogen (N), phosphorus (P), and potassium (K). k-carrageenan-induced alterations were noted in the contents of essential oil compounds. These results suggest that k-carrageenan can be a growth-promoting agent and significantly enhance essential oil yield, particularly in O. basilicum plants.