Effects of drought stress on growth and physiological characteristics of roselle (Hibiscus sabdariffa L.)

Drought is the major abiotic stress which causes major losses to agriculture production. This study was conducted to determine the effect of drought stress on the growth and physiological characteristics of Hibiscus sabdariffa. The drought stress treatments were 33, 67 and 100% of the field capacity. Each treatment was replicated five times in a randomized complete block design. According to the results, drought stress had significant effects on the growth and physiological traits of H. sabdariffa. As the drought stress increased, the plant height, leaf area, specific leaf area, fresh and dry weight of shoot and root, photosynthetic rate, stomatal conductance, intercellular CO2 concentration and the transpiration rate decreased. The root-shoot ratio was significantly increased in stressed plants. The changes in number of branches per plant and chlorophyll content were, however, not significant. These findings suggested that H. sabdariffa might be able to tolerate drought stress by increasing the root-shoot ratio and stability of chlorophyll content

Impact of drought on gas exchange and yield parameters in roselle (Hibiscus sabdariffa L.)

Effect of drought stress on gas exchange and yield parameters in roselle (Hibiscus sabdariffa L.) was investigated under pot culture conditions in rainout shelter. Experiment was laid out in a randomized complete block design with five replications and three treatments viz, 100%, 67% and 33% field capacity. As the stress increased, reduction in photosynthesis rate, stomatal conductance, intercellular CO2 concentration and transpiration were observed. The number of fruits, fruits weight and calyx yield per plant were not significantly different at 100% and 67% field capacity. These findings suggested that optimum calyx yield can be obtained at 67% field capacity