Durum wheat and barley productivity in saline–drought environments

Abstract

In two successive years, durum wheat ( Triticum turgidum Desf.) and barley ( Hodeum vulgare L.) were tested in a factorial salinity–drought experiment, combining three levels of salinity and two levels of drought. The two drought treatments were obtained by applying irrigation water when the pre-dawn leaf water potential of the control treatments attained values of −0.4 and −0.7 MPa, respectively. This experiment led to the analysis of the effects of salinity, of drought, and of the drought–salinity interaction on the grain and straw yield of the two crops studied. Salinity affected the durum wheat by reducing the grain and straw yields when the soil salinity (EC e) was higher than 5.8 dS m −1. This reduction was due to the fact that there were fewer grains per ear. As for barley, the grain yield was not reduced if EC e ranged from 0.9 to 9.8 dS m −1, but the straw yield was affected. The results obtained for durum and barley are consistent with the observations reported in the literature. Drought affected the plant water status of both species during the ear formation and flowering stages. It reduced the grain (37%) and straw (18%) yields, on average, at the same rate for all salinity levels. These reductions were not related to the soil salinity levels. There were fewer ears per plant, explaining the decrease in crop productivity and water use efficiency in conditions of drought. Drought did not affect the relationship between soil salinity and relative yield.