EFFECT OF IRRIGATION TREATMENTS UPON THE CHEMICAL-CONSTITUENTS OF HIBISCUS-SABDARIFFA L

The present investigation was carried out to study the effect of irrigation regimes (irrigation levels and irrigation intervals) upon the chemical constituents of Hibiscus sabdariffa. The results can be summarised as follows: 1. The treatment of 100 m3/irrigation water/irrigation/feddan* as well as 35 and 45 days intervally irrigated treatments resulted in a highly significant increase in the total soluble solids percentage of fruit calyx beverage. 2. The acidity of the fruit calyx beverage had the same value under the various treatments in both the two experiments of irrigation treatments. 3. The synthesis of anthocyanins and flavones which are responsible for the red color in the fruit calyx of Hibiscus sabdariffa was significantly stimulated by the treatment of 150 m3 irrigation water/irrigation/feddan as well as the 15 days intervally irrigated treatment. Therefore an increase in the reddish color of Hibiscus sabdariffa fruit calyx could be attained by irrigating the plant with 150 m3 water at 15 days intervals during the plant life cycle. © 1979 Martinus Nijhoff.