Tolerance to mid-season drought in peanut can be achieved by high water use efficiency or high efficient use of water

Peanut (Arachis Hypogaea L) is an economic cash crop mainly planted in arid and semi-arid regions where drought causes approximately 20% yield losses every year. It has been demonstrated that drought tolerance can be achieved by two different mechanisms in plants: either by saving water or by extracting more water from the soil (water spender genotypes). The objective of this research was to screen for these twomechanisms of drought tolerance in peanut. Plants were grown in rainout shelters under irrigated conditions until mid-pod filling, then drought was induced using rainout shelters. Gas exchange parameters were measured regularly during the drought period and recovery. Genotypes PI 502120 and AU-NPL 17 were classified as water spender genotypes as they showed high yield,.13C, photosynthesis, and stomatal conductance under drought. This is the first time that water spender genotypes have been identified in peanut. On the other hand, genotypes Line-8 and AU16-28 were classified as water savers as they showed equally high yields but with low.13C and stomatal conductance and moderate photosynthesis under drought stress. In this study, water spender genotypes did not show a yield advantage in comparison with water savers.