Barley Culivars Compared Under an Irrigation Water Gradient

The relative ability of barley cultivars to perform outside the environment for which they were selected is not fully known. This study was initiated at Marana in 1985-86 to compare barley cultivars, which were adapted to different input levels, under a line-source sprinkler system that delivered a gradient of water. Higher than average rainfall in February and March provided ample moisture for crop growth, prevented very low water levels and led to the water gradient being applied late in the season when most of the cultivars were in the grain fill stage. We determined that cultivars bred for high level management (Gustoe and Barcott) performed best at the high water levels. Suitable cultivars for minimal water could not be determined since truly low water levels were never attained. Harvest index, the proportion of grain to total plant yield, was greatest for Gustoe at the high water level, but no differences were detected at the low water level. We suspect that one-irrigation barleys, bred to produce grain with a single preplant irrigation, effectively recover water with a deep root system and do not necessarily use less water than other barley cultivars