The use of sawdust-fortified topsoil as a growing medium has emerged as a promising approach to promote increase in yield and promotion of sustainability in agriculture. Given that different crops have varying soil requirements, it is essential to determine the optimal ratio of sawdust to topsoil for each crop. This study investigates the effect of sawdust-fortified topsoil on the growth and development of mini-stem propagated plantain suckers, using the detached corm (split) technique—a macropropagation method used in generating healthy plantain mini-stems. This experiment compared the effect of varying ratios of topsoil (TS) and sawdust (SD), namely, 100TS (control), 50TS50SD, 60TS40SD, and 70TS30SD, on plantain mini-stems. Growth parameters recorded across five replicates per treatment included stem height, stem girth, leaf number, and leaf area. Data were analyzed using ANOVA via SPSS.

The result showed that all treatments positively influence growth parameters, with Treatment 4 (70TS30SD) showing the most significant effect on stem height, stem girth, and leaf area. This outcome is attributed to a balance ratio between sawdust and topsoil resulting to improved soil structure, balanced nutrient availability, optimal aeration, and water retention.

This study suggests that fortifying topsoil with sawdust, particularly at the ratio of 70TS30SD, can improve the sprouting rate, growth, and development of mini-stem propagated plantain suckers. This finding therefore presents a viable and sustainable alternative to traditional propagation media (i.e., topsoil only) in plantain production. It also provides farmers around tropical regions with a clear practical ratio to adopt.