Growth and water relations of Kenaf (Hibiscus cannabinus L.) under water deficit on a sandy soil

The effects of water stress on growth and water relations of Kenaf (Nibiscus cannabinus L.) were investigated. The plants were grown on a loose-textured sandy soil in the greenhouse at CERAAS, Bambey, Senegal. Three watering regimes representing well watered control, moderate stress and severe stress were imposed on the plants. Each watering treatment was replicated four times in a completely randomized design. Soil moisture stress significantly retarded vegetative growth as analysed by plant height, collar diameter growth, leaf development, branching, flowering, and biomass accumulation. Water stress had no effects on biomass allocation, in terms of root-shoot and bark-wood ratios. Kenaf tried to avoid drought by leaf rolling and stomatal closure. The water potential (psi(w)) went as low as -2.53 MPa under severe stress, and -0.50 MPa was bracketed as the most critical psi(w), below which stomatal conductance and transpiration ceased and leaf-air temperature differential became positive. (C) 1998 Elsevier Science B.V. All rights reserved.