Preliminary Evaluation of Yield and Storage-root Characteristics of Sweet Potato Genotypes under Mineral Soil Conditions

Abstract

Sweet potato yield is influenced by complex relationships among vegetative growth, storage-root characteristics and genotype. This study evaluated variation in vegetative, storage-root and yield traits among the 14 sweet potato [Ipomoea batatas (L.) Lam.] genotypes grown under mineral-soil conditions at MARDI Jerangau, Terengganu, Malaysia (N 04 57' 22", E 103 10' 05"), from June to October 2025. The experiment was arranged in a randomised complete block design with three replications, and ten quantitative traits were measured. Data were analysed using analysis of variance, Tukey’s post hoc test, Pearson correlation analysis and principal component analysis (PCA). B1 had the numerically highest estimated yield (12.29 t ha⁻¹), followed by V6 (11.26 t ha⁻¹), V1 (10.63 t ha⁻¹) and V8 (10.52 t ha⁻¹), while KB produced the lowest yield (1.15 t ha⁻¹). V8 recorded the highest storage-root weight per plant (971.44 g) and number of storage roots per plant (6.55). Storage-root weight per plant was positively correlated with root number (r = 0.558, P < 0.01), average root weight (r = 0.808, P < 0.01), root diameter (r = 0.750, P < 0.01) and estimated yield (r = 0.455, P < 0.01). Three principal components accounted for 83.07% of the total variation, with PC1 accounting for 47.00% and primarily representing storage-root biomass, size and yield. Overall, B1, V6 and V8 exhibited promising productivity-related characteristics and should be prioritised for advanced multi-location and multi-season evaluation. These findings provide preliminary selection information, but broader testing is required before recommendations on yield stability or cultivar suitability can be made.