Abstract
An ever-growing challenge to agricultural production worldwide is the reduced availability of water and increased incidence of drought. The development of low-irrigation barley cultivars marks a significant achievement in breeding efforts for drought tolerance, but specific traits conferring adaptation to water stress remain unclear. Here, we report results from two years of replicated field trials comparing yield, phenology, water usage, and rooting characteristics of low-irrigation varieties “Solar” and “Solum” to high-input, semi-dwarf varieties “Kopious” and “Cochise”. The objective was to identify differential performance of varieties under high- and low-water conditions through comparison of growth and developmental traits. Rooting characteristics were analyzed by digging in-field root profile walls to a depth of 1.8 m. Varieties were compared under high (877 mm) and low (223 mm) water regimes including irrigation and precipitation. Observed traits associated with improved performance of the low-irrigation varieties under drought conditions included early vigor, early flowering, greater root growth at 40–80 cm depth, and more effective water use exhibited by greater water extraction post-anthesis. The deeper rooting pattern of the low-irrigation varieties may be related to their ability to use more water post-anthesis under water stress, and thus, to fill grain, compared to high input varieties.
Highlights
Barley has demonstrated a capacity to thrive in arid and semi-arid climates where drought is a determinant of crop productivity
Fraction of photosynthetically active radiation intercepted by the crop differed among varieties depending on irrigation treatment and year (Table 3)
Under HI in 2015, Fraction of photosynthetically active radiation (fPAR) was higher for the high-input varieties at first and last sampling, and in 2018 there was no difference between groups
Summary
Barley has demonstrated a capacity to thrive in arid and semi-arid climates where drought is a determinant of crop productivity. The projected increase in incidence and severity of drought conditions combined with the predicted decline in water availability has sparked interest in crop production that is less water dependent [1,2]. Major drought tolerance traits assessed in this study relate to crop growth, water use, and yield. Season canopy cover reduces evaporation from the soil surface leaving more water available for crop growth [9,10,11]. Plant height under drought stress compared to under non-stress conditions is an indicator of crop drought tolerance as is the allocation of carbohydrate reserves to grain filling, expressed by harvest index [12,13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
