Saline/Sodic sub-soil on triticale, durum wheat and bread wheat yield under irrigated conditions

Sub-soil (> 30 cm) salinity and sodicity is a growing problem particularly in irrigated agricultural areas with rising water tables, poor water quality and/or deficient soil drainage. There were two objectives in this study; (1) to quantify the effect of sub-soil salinity and sodicity in grain yield of triticale, bread wheat and durum wheat and, (2) to determine if genotypes within and between these three crops interact in a normal soil and one with a saline/sodic sub-soil under irrigated conditions. The soils at the CIMMYT experiment station in Cd. Obregon, Sonora, Mexico were mapped by kriging with GS+ geostatistical software for all chemical properties and soil texture. Using the soil maps, two contrasting areas of the station where identified. One with a saline/sodic sub-soil and the other with a normal soil (no limiting factors). A two year experiment was established with sixteen genotypes that included six bread wheats (1-6), five durum wheats (7-11) and five triticales (12-16) in the two soil types previously identified. The results showed a 10% yield reduction when all sixteen genotypes were averaged in the saline/sodic sub-soil location compared to the one with the normal soil. Average across genotypes all three crops seem to have the same level of tolerance to sub-soil salinity/sodicity. However, there was an interaction among genotypes for tolerance to sub-soil salinity/sodicity within each crop. Seven out of the sixteen (44%) genotypes evaluated were tolerant indicating a high frequency of tolerance to this soil problem in the CIMMYT germplasm. Breeders should be aware of the genotype x soil interaction present in bread wheat, durum wheat and triticale at the research station and insure that their trials are planted in soils that represent their breeding objectives.