THE EFFECTS OF FLUORIDE STRESS ON OKRA (ABELMOSCHUS ESCULENTUS L.)

The influence of sodium fluoride on two cultivars of okra (Nirali and Arka Anamika) was evaluated during the seedling and growth stages, by applying different concentrations of NaF (50, 100, 150, 200, 250, and 300 ppm). All the parameters studied showed a greater reduction with the higher concentrations of sodium fluoride (250 and 300 ppm) than with the lower concentrations (50 and 100 ppm). In cultivar Nirali, the plants treated with 300 ppm NaF showed reduction percentages in the shoot and root fresh weight, of 84% and 90%, respectively, while the corresponding reductions in Arka Anamika were 82% and 91%. Increased concentrations of fluoride can significantly decrease plant pigment levels (chlorophyll a & b, total chlorophyll, and total carotenoids), the total soluble sugar, and the protein content. In contrast, increasing concentrations of sodium fluoride, increased the proline content significantly.