Variation in yield of grain and biomass in wheat, barley, and triticale in a salt-affected field

Abstract

Thirty-eight genotypes of hexaploid and tetraploid wheats, triticale, and barley varying in foliar sensitivity to salinity were grown in a replicated experiment on a salt-affected site in the San Joaquin Valley of California. Electrical conductivity of the saturation extract from the 5–30 cm soil zone varied between 2 and 70 dSm −1. At maturity, yield of grain and above-ground biomass of every genotype was determined from areas showing visual evidence of high, intermediate, and low amounts of salt damage. The bulk soil electrical conductivity 0–30 cm below the soil was also determined in each sample area. A negative linear relation was found for yields of grain and biomass with soil salt concentration. Significant differences among genotypes were observed in the slope of the regression lines indicating genotype × soil salinity interactions. Considerable variation was also found in the predicted yields at high and low salt concentrations, in yield loss per unit change in electrical conductivity and in the predicted salt concentration at which no yield was produced. No clear-cut association was observed between visual ratings of foliar damage and yield of biomass at high or low salt concentrations. Furthermore, no relation was found between yields at low salt levels and either the predicted salt concentration causing death or yield at high salt levels. The implications of this study for cereal improvement in salt affected areas is discussed. Where salinity is patchy, selection for yield at low salinity levels would seem the most efficient way to increase yields.