“…Water stress may be determined by measuring physiological parameters such as leaf water potential, leaf osmotic potential, osmotic adjustment, leaf diffusive resistance (LDR), leaf relative water content (RWC), leaf temperature, leaf thickness, leaf rolling (Turner, 1981), proline content (Bates, Waldren & Teare, 1973) and cell membrane stability (Sullivan & Ross, 1979;Blum & Ebercon, 1981).…”