Efficiency of Water Use and Associated Characteristics of Lehmann Lovegrass

Abstract

Efficiency of water use of five lines and the cultivar 'A-68' of Lehmann lovegrass (Eragrostic lehmanniana Nees) was related to seedling drought tolerance and to physiological and morphological plant characteristics. Components of efficiency of water use (transpired water and dry matter produced) and the values of water-use efficiency (measured as the number of units of transpired water per unit of dry matter produced) varied among lines. Line L-38 was most efficient in water use (water-use efficiency value of 135), had the highest percentage of survival, 32.4%, (seedling drouth tolerance) and produced the most dry matter (8.31g). The ratios of maximum recorder deflection of petroleum ether extract and the total area of optical deflection of petroleum ether extract to dry weight of leaves were variable among lines and significantly associated with efficiency of water use and seedling drouth tolerance. High deflection values were associated with high efficiency of water use and high percentage of survival. Stomate density was different among lines and was higher on the upper surface than on the lower surface of the leaf blade. Stomate density was not significantly associated with efficiency of water or seedling drouth tolerance.