Substrate composition influences growth performance of Dwarf Rotala (Rotala rotundifolia)

Abstract

The aquatic plant Rotala rotundifolia, commonly known as dwarf rotala, is valued for its ornamental and medicinal properties. Substrate composition influences plant growth in height and colonization, which is important for commercial propagation. This study investigated the impact of substrate composition on growth performance by evaluating four substrate mixtures: paddy soil: top soil (1:1) as the control, and paddy soil: top soil combined with either gliricidia, cow dung or coconut coir in a 5:4:1 ratio. One healthy apical stem of R. rotundifolia (6.3cm) was planted in each plastic pot containing 1.5 inches of respective mixture, with water levels maintained below the substrate interface. Each treatment had four replicates. Plants were grown under natural light for three weeks. Plant growth performance was assessed based on total height, wet and dry weights and leaf characteristics. Plants cultured in the control and cow dung treatments showed the significantly (p<0.05; One way ANOVA) higher total plant height (18.34±1.41cm and 18.08±0.50cm, respectively) and shoot height (14.00±1.29cm and 13.16±1.28cm, respectively) compared to the other two treatments. However, the number of leaves, wet weights of the plants, wet weights of the shoots and roots were not significantly different among treatments. The highest percentage of shoot dry weight (86.43±3.38%) and lowest percentage of root dry weight (13.56±3.38%) were observed in the control treatment. Therefore, a substrate composition of paddy soil: top soil (1:1) is recommended for optimal growth performance of R. rotundifolia.