EFFECT OF WATER POTENTIAL ON SEEDLING GROWTH OF SORGHUM CULTIVARS

A Laboratory experiment was conducted to evaluate the effect of five levels of water potential (ψw) viz., 0.00; -0.41; -0.82; -1.23 and -1.64 MPa on the seedling growth of six cultivars of sorghum (Sorghum bicolor L.). Mannitol was used as osmoticum alongwith half strength Hoagland culture solution. Results enumerated that in response to various levels of water potential all mentioned attributes of seedling growth (except shoot dry weight) as well as different cultivars responded significantly (P 0.05). Results also enumerated that as water potential level increases most of the growth attributes are inversely decreases. Generally a maximum reduction in root length (5.54 cm seedling-1), shoot length (9.63 cm seedling-1), root fresh weight (19.00 mg seedling-1) and shoot fresh weights (33.33 mg seedling-1) are recorded in higher water potential levels (-1.23 and -1.64 MPa). Results further stated that based on cumulative drought tolerance index (%), sorghum cv. ICSH=479 could be ranked as drought tolerant and cv. S.E.T P=14-2 as drought sensitive. While, remaining four cultivars viz., Giza-3; ICSV=107; 1747 and Pak S.S.II could be ranked as drought intermediate in response, respectively