Semi-dwarf bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L., Durum Group) are often grown on saline soils in the western United States. Because of the lack of information on salinity effects on vegetative growth and seed yield of these two species, a 2-yr field plot study was conducted. Six salinity treatments were imposed on a Holtville silty clay (clayey over loamy, montmorillonitic (calcareous), hyperthermic Typic Torrifluvent) by irrigating with waters salinized with NaCI and CaCI, (1:1 by wt). Electrical conductivities of the irrigation waters were 1.5, 2.5, 5.0, 7.4, 9.9, and 12.4 dS/m the first year, and 1.5, 4.0, 8.0, 12.0, 16.1, and 20.5 dS/m the second year. Grain yield, vegetative growth, and germination were measured. Relative grain yields of one semi-dwarf wheat cultivar and two durum cultivars were unaffected by soil salinity up to 8.6 and 5.9 dS/m (electrical conductivity of the saturatedsoil extract), respectively. Each unit increase in salinity above the th~esholds reduced yield of the semi-dwarf cultivar by 3.0% and the two durum cultivars by 3.8%. These results place both species in the salt-tolerant category. Salinity increased the protein content of both grains but only the quality of the durum grain was improved. Vegetative growth of both species was decreased more by soil salinity than was grain yield. Both species were less salt tolerant at germination than they were after the three-leaf stage of growth.

The salt tolerance of crops has usually been studied under optimal fertility conditions. The objectives of the present studies were to compare crop response to salinity when nutrients were limiting, adequate, or in excess to guide proper fertilization of saline soils and to determine whether additional fertilizer could restore yield losses caused by salinity. Corn (Zea mays L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and six vegetable crops were grown to maturity in large, outdoor sand cultures to study the interactive effects of salinity and nutrition. Increasing levels of phosphate (0.1 to 2.0 mM) aggravated salt injury in corn and decreased salt tolerance. Decreasing solution K from 2 to 0.4 meq/liter did not affect leaf K or yield of corn. Deficient levels of P or N did not consistently decrease salt tolerance of any of the crops studied, although the wheat and barley varieties showed erratic decreases in salt tolerance when N or P was deficient. When N or P was severely growth‐limiting, salinity affected growth of some crops [broccoli (Brassica oleracea var. capitata), cabbage (B. oleracea var. botrytis)] less. Conversely, when salinity severely limited growth, nutritional responses of some crops decreased. Salinity did not aggravate N or P deficiency as judged by leaf N and leaf P contents. Effects of salinity and N or P deficiency on other mineral constituents were highly crop specific.

Grain sorghum (Sorghum bicolor (L.) Moench) is grown on saline soils in the western United States. Because of the lack of information on salinity effects on seed yield, a field plot study was conducted. Six saline treatments were imposed on a Holtville silty clay (clayey over loamy montmorillonitic (calcareous), hyperthermic Typic Torrifluvents) by irrigating with waters that were salinized with NaCl and CaC1 2 (1:1 by wt). The electrical conductivities of the irrigation waters were 1.5, 2.7, 5.0, 7.4, 9.8, and 12.1 dS/m. Germination, vegetative growth, and grain yield were measured. Relative grain yield of two cultivars, Double TX and NK-265, was unaffected up to a soil salinity of 6.8 dS/m (electrical conductivity of the saturation extract: «.). Each unit increase in salinity above 6.8 dS/m reduced yield by 16o/o. This indicated that grain sorghum is moderately tolerant to salinity. Yield reduction was due primarily to lower weight per head rather than a reduced num!Jer of heads. Vegetative growth was affected less by increasing soil salinity than was grain yield. Grain sorghum was significantly more salt tolerant at germination than at later stages of growth.------------------A.dditwlllll indu words: Sorghum bicolor (L.) Moench, Salt tolerance, Sodium chloride, Calcium chloride.

Sunflower (Helianthus annuus L.) is becoming an increasingly important source of edible vegetable oil throughout the world because of its high polyunsaturated fatty acid content and no cholesterol. The increasing demand for this oil may promote increased hectarage of sunflower in the western USA, where some soils are saline or have the potential to become so. Since there is little information concerning the response of sunflower grown under saline conditions, a 2‐yr field plot study was conducted. Six salinity treatments were imposed on a Holtville silty clay (clayey over loamy, montmorillonitic [calcareous], hyperthermic Typic Torrifluvent) by irrigating with Colorado River water artificially salinized with NaCl and CaCl2 (1:1 by weight). Electrical conductivities of the irrigation waters both years were 1.4 (control), 2.0, 3.0, 4.0, 6.0, and 8.0 dS m−1. Seed yield and oil content of the seed were measured. Relative seed yield of four hybrids was unaffected by soil salinity up to 4.8 dS m−1 (electrical conductivity of the saturation extract, ECe). Each unit increase in salinity above 4.8 dS m−1 reduced yield by 5.0%. These results indicate that sunflower is appropriately classified as moderately tolerant to salinity. Yield reduction was attributed primarily to a reduction in seeds per head. Oil concentration in the seed was relatively unaffected by increased soil salinity up to 10.2 dS m−1. Sunflower appears to be well adapted for growth under moderately saline soil conditions.

Due to health concerns regarding saturated fat in the human diet, canola (Brassica spp.) is becoming an increasingly important source of edible vegetable oil because of its low saturated fat content. This increased demand, and the need for crop diversification, will undoubtedly promote increased acreage of canola in the western USA, where some soils are or have the potential to become saline. Salt tolerance in two canola species (B. napus L. cv. Westar and B. campestris L. cv. Tobin) was determined in a 2‐yr field plot study. Six salinity treatments were imposed on a Holtville silty clay (clayey over loamy, montmorillonitic [calcareous], hyperthermic Typic Torrifluvent) by irrigating with waters salinized with NaCl and CaCl2 (1:1 w/w). Electrical conductivities of the irrigation waters ranged from 1.2 to 9.7 dS m−1 the first year, and 1.2 to 11.5 dS m−1 the second year. Seed yield, vegetative growth, oil content, and protein content in the oil‐free seed meal were measured. Relative seed yields of Westar and Tobin were unaffected by soil NaCl and CaCl2 (1:1 w/w) 9.7 dS m−1 (electrical conductivity of the saturated soil extract: ECe), respectively. Each unit increase in salinity above the thresholds reduced the seed yield of Westar by 13.0% and Tobin by 14.3%. These results place both canola species in the salt‐tolerant category. Increased salinity did not significantly affect the oil or protein content of the oil‐free seed meal. Vegetative growth of both species was unaffected by soil salinity up to 10.0 dS m−1 and the growth decline above this threshold was 11.2% per unit increase in salinity.