Climatic and Water Availability Effects on Water-Use Efficiency in Wheat

Abstract

purposes and to adopt management practices that allow WUE to be maximized. In Argentina, wheat (Triticum aestivum L.) is cropped over a wideIn Argentina, wheat is mainly cropped from 32 to range of climatic conditions. Considerable variability in the ratio of 39ЊS and 57 to 63ЊW (Hall et al., 1992). Considerable dry weight produced per unit of transpired water, usually referred to variability in climatic conditions and WUE is expected as water-use efficiency (WUE), is expected as variation in climatic factors affects photosynthesis and transpiration in different ways. throughout this zone. Several authors have proposed Also, previous studies have shown that water supply limitations may the use of environmental indexes to explain changes in affect WUE in wheat. The objective of this study was to quantify the WUE across environments. Some of the most frequently effects of climatic environment and water availability on WUE in used indexes were mean pan evaporation (de Wit, 1958), wheat crops. Six experiments were conducted at different locations mean relative humidity (Arkley, 1963), mean vapor of the Argentine wheat belt and crop dry weight and water use were pressure deficit (VPD) (Bierhuizen and Slatyer, 1965), measured in periods when water use was dominated by transpiration. and mean potential water use (Doorenbos and Kassam, Three of the experiments included both irrigated and rainfed treat-1979). Vapor pressure deficit is a widely used and conments. Mean daily values of (i) pan evaporation, (ii) relative humidity, cise index that explains changes in the ratio yield/water (iii) potential water use, and (iv) vapor pressure deficit, were used use (Angus and van Herwaarden, 2001). The effect of to find a general relationship that explained effects of the climatic VPD on WUE has been reported for corn (Zea mays environment on WUE. For experiments with high water availability, L.), sorghum [Sorghum bicolor (L.) Moench], potato daytime vapor pressure deficit was better related to WUE than the (Solanum tuberosum L.), alfalfa (Medicago sativa L.), other climatic factors. WUE was greater for experiments with water soybean [Glycine max (L.) Merr.] (Tanner and Sinclair, limitation, probably because stomatal closure to restrict transpiration rate occurred around midday when vapor pressure deficit was highest. 1983), and barley (Hordeum vulgare L.) (Monteith, As a consequence, relative dry weight under water limitation was not 1986). Comparisons of the abilities of different meteorolinearly related to relative water use as proposed in previous studies.

Crop yield and water use efficiency in semi-arid region of Turkey

“…Often its effectiveness could not be observed if stubbles were not retained (O'Leary and Connor, 1997). Nevertheless, our study showed that fallow treatment was among one of the most efficient in water use with a WUE of 8.4 kg/(ha mm À1 ) average over two years and was similar to findings in other dryland regions of the world (Zhang et al, 1998;Abbate et al, 2004).…”

Drought Stress Responses in Plants, Oxidative Stress, and Antioxidant Defense

“…The reduction of water potential is also greatly dependent on crop species, varieties, and level of stress. However, Abbate et al [72] and Subramanian et al [73] reported higher WUE in wheat and tomato under drought than well-watered controls, which was mainly due to the reduced transpiration rates under drought. For instance, drought-tolerant genotypes maintained a higher leaf water potential for longer and wilted later than sensitive genotypes upon exposure to drought [69].…”

The opening of Pandora’s Box: climate change impacts on soil fertility and crop nutrition in developing countries

“…However, any positive effects of warmer temperature on nutrient capture are dependent on adequate soil moisture. If under dry conditions higher temperatures result in extreme vapor pressure deficits that trigger stomatal closure (reducing the water diffusion pathway in leaves) (Abbate et al 2004), then nutrient acquisition driven by mass flow will decrease (Cramer et al 2009). Temperature driven soil moisture deficit slows nutrient acquisition as the diffusion pathway to roots becomes longer as ions travel around expanding soil air pockets (Brouder and Volenec 2008).…”