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Joseph G. Robins, B. Shaun Bushman, Blair L. Waldron, and Paul G. Johnson

with sufficient salinity tolerance ( Alshammary et al., 2004 ). Additionally, large areas of the world are characterized by soils with high levels of salt. Oldeman et al. (1991) estimated that ≈80 M ha of arable soil is salt-affected worldwide. Thus

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Chenping Xu and Beiquan Mou

Salinity of soil and irrigation water is a growing problem for agricultural production in the world. It is estimated that salt-affected soils impact on nearly 10% of the land surface and 50% of irrigated land in the world ( Ruan et al., 2010

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Yiming Liu, Hongmei Du, Kai Wang, Bingru Huang, and Zhaolong Wang

Salinity is one of the major abiotic factors limiting plant growth in many areas of the world, which is progressively increasing as a result of the decline in fresh water for irrigation and increasing use of effluents that contain concentrations of

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Glenn C. Wright, Kim D. Patten, and Malcolm C. Drew

`Tifblue' rabbiteye blueberry (Vaccinium ashei Reade) and `Sharpblue' southern highbush blueberry (primarily V. corymbosum) were treated with 0, 25, or 100 Mm Na+ as Na2SO4 or NaC1, and 0, 1, 3, or 10 Mm supplemental Ca2+ in sand culture in the greenhouse. Greatest stomatal conductance (gs) and net assimilation (A) occurred in unsalinized `Tifblue' plants not given additional Ca2+. Stomatal conductance, A, transpiration (E), and xylem water potential(Ψ)of `Tifblue' and `Sharpblue' plants were all lowered as salinity increased, and these effects were more pronounced with NaCl than with Na2SO4. After 63 days, for plants given 100 Mm Na+ as NaCl, gs and net assimilation rate were reduced to only 10% of the unsalinized controls, while for plants salinized with 100 mm Na+ as Na2SO4, gs and A were 35% and 43%, respectively, of unsalinized controls. Leaf necrosis was more extensive on `Sharpblue' plants given NaCl than on `Tifblue' plants. Neither Ca2+ nor Na+ treatments led to severe chlorosis; reductions in leaf chlorophyll content were mainly due to necrosis. The Na+- induced reduction in gas exchange was associated with negative Ψw Ca2+ deficiency, or a combination of these factors. Additional factors leading to inhibition of gas exchange in NaCl- stressed plants include Cl- toxicity and leaf necrosis. Calcium supplements were unable to ameliorate NaCl damage in `Tifblue' or `Sharpblue' plants, possibly because of the inability of Ca2+ to counter Cl- entry and toxicity. In contrast, additional Ca2+ improved gs, A, Ψw, and leaf chlorophyll content of `Tifblue' plants that received Na2SO4. For plants treated with 25 mm Na+ as Na2SO4 and 1 mm Ca2+, gs was 1.5 to 2.5 times higher than in plants without added Ca2+. Low (1 mm) concentrations of Ca2+ were more effective in ameliorating the effects of 100 mm Na+ as Na2SO4. than were 3 or 10 mm Ca2+ supplements, possibly because higher Ca2+ concentrations damaged the metabolism of the calcifuge blueberry.

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Y.L. Qian, J.M. Fu, S.J. Wilhelm, D. Christensen, and A.J. Koski

salinity problems in many urbanized areas of the western United States ( Carrow and Duncan, 1998 ; Qian and Mecham, 2005 ). Turfgrass managers are struggling to produce quality turf on sites with high salinity and irrigated with marginal-quality water

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Manuel Chavarria, Benjamin Wherley, James Thomas, Ambika Chandra, and Paul Raymer

Water quantity and quality are major issues of concern around the world, particularly in arid and semiarid areas where water shortages have resulted from rapid urbanization, agriculture, and/or industry ( Huang et al., 2014 ). Elevated salinity is

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Qi Zhang, Sheng Wang, and Kevin Rue

High soil salinity is one of the major limitations to plant growth in the northern Great Plains. A survey showed that high levels of soil sodium and salinity were detected in 1,900,000 and 700,000 acres of land in North Dakota, respectively ( Seelig

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James P. Syvertsen, Juan C. Melgar, and Francisco García-Sánchez

There is a wide range of plant growth and physiological responses to excessive salt ion accumulation and osmotic stress from high salinity ( Yeo and Flowers, 1989 ). Due to the complexity of salt tolerance in crops ( Flowers and Flowers, 2005

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Maren E. Veatch-Blohm, Douglas Sawch, Nicole Elia, and Dominic Pinciotti

Salinity is a major obstacle for crop production throughout the world. At least one-third of agricultural land is salinized and the amount impacted by salinization is expected to increase ( Carter et al., 2005 ; Cassaniti et al., 2009 ; Munns and

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Qi Chai, Xinqing Shao, and Jianquan Zhang

Salinity has been recognized as a major factor limiting crop productivity in many areas of the arid regions of the world where soil salt content is naturally high and precipitation is insufficient for leaching ( Chinnusamy et al., 2005 ; Flowers