Cluster Heatmap Analysis–Based Evaluation of Sugar Beet Varieties for Yield and Quality Traits under Saline Soil Conditions Enhanced by Sal-Wax-Ca rates

Improving crop productivity on marginal, especially saline soils require environmentally friendly approaches and careful identification of tolerant varieties. A field experiment was conducted during two consecutive growing seasons at a private farm in the Ismailia Governorate, Egypt, to evaluate the performance of six monogerm sugar beet varieties (Albus, Goelette, Prodessa KWS, Geizer, Tornadoo, and Spectra) under saline soil conditions. The study also examined yield and quality responses to four application rates of Sal-Wax-Ca (0, 0.5, 1 and 1.5 kg/fed). Applying Sal-Wax-Ca during early growth stages enhanced crop growth and improved plant tolerance to salinity. Increasing rates of Sal-Wax-Ca significantly improved root yield, sugar yield, and related growth traits compared with untreated control. Higher rates also reduced impurity parameters, such as sugar lost to molasses (SLM %) and concentrations of Na, K, and N, across both seasons, contributing to improved sugar extraction quality. Among the evaluated varieties, Albus variety exhibited the highest tolerance and productivity under salinity, recording superior crop growth rate, total chlorophyll content, root diameter, sucrose percentage, and root and sugar yields (ton/fed). In contrast, Spectra consistently recorded the lowest values for most growth, yield, and quality parameters. Hierarchical clustering showed that the 1.5 kg/fed Sal-Wax-Ca treatment clustered distinctly with the Albus, Goelette, and Tornadoo varieties, indicating a strong positive response to the amendment under salinity stress. Correlation analysis and heat-map clustering further highlighted the interrelationships among and growth, yield, quality, traits, uncovering patterns not evident through conventional statistical methods.