Effect of Soil Types and Cultivars on Chemical Constituents of Roselle (Hibiscus sabdariffa L.) under growing conditions of Sudan
The effect of two soil types, namely Shambat soil (Vertisol) and Soba soil (Entisol) on the performance of four cultivars of Hibiscus sabdariffa L. (namely: Rahad, Fashir, Kass and Abiad)- was studied by evaluating some of its constituents as, organic acids (citric, ascorbic and tartaric), Anthocyanines (malvidin and pelargonidin), pH and essential amino acids under the semi -arid conditions of Sudan. HPLC and amino acid analyzer were used in this study. It was found that, there was a significant effect of type of soil on pH, organic acids and essential amino acids content where, Shambat soil gave significantly higher pH values, total organic acids, and amino acids than those grown in Soba soil. But, there was a significant difference between soil types on organic acids separately, where, cultivars grown in Soba soil gave significantly higher amount of citric and ascorbic acid content than those grown in Shambat soil, while tartaric acid was the highest in cultivars  cultivated in Shambat soil. Anthocyanines also were significantly affected by type of soil, where Malvidin was found to be higher in Shambat soil than Soba soil, but pelargonidin was higher in Soba soil, but there were no significant effect on total anthocyanines. With respect to cultivars it was found that, there was no significant different among cultivars in the pH, while the organic acids were significantly affected, where, Fashir cultivar contains the highest amount of total organic acids. On the other hand, Rahad cultivar gave significantly the highest amount of the Anthocyanines and essential amino acids content among all other cultivars.