Effects of Ridge Size on the Growth and Yield of Potatoes (Solanum Tuberosum L.) in Chilanga District, Zambia

This study investigated the effect of ridge size on the growth and yield of potato (Solanum tuberosum L.) under field conditions in Chilanga District, Zambia. An experimental design was employed, testing five ridge widths (30 cm, 50 cm, 61 cm, 75 cm, and 90 cm) in a Randomized Complete Block Design (RCBD) with three replications. Data was collected on plant growth parameters (height, canopy width) and yield parameters (tuber count, average tuber weight, total yield). The findings revealed that ridge size had a highly significant (p<0.0001) effect on all measured variables. Increased ridge width resulted in enhanced plant height and canopy diameter. Crucially, wider ridges significantly increased the average weight of individual tubers and the total yield per hectare. The 90 cm ridges produced the highest average tuber weight (163.67 g), while the 75 cm and 90 cm ridges yielded the highest total yields (35.8 t/ha and 36.2 t/ha, respectively), significantly outperforming the 30 cm ridges (25.1 t/ha). The study concludes that ridge size is a critical agronomic factor for potato production. It is recommended that farmers in similar agro-ecological zones adopt a ridge width of 75 cm as it provides an optimal balance between maximizing yield and managing land preparation costs, thereby enhancing productivity and profitability for small and medium-scale farmers.