Effect of Irrigation Treatments Using Treated Wastewater On Grain Yield of Four Barley Cultivars.

Two field experiments were conducted during the 2010/2011 growing season to assess the effect of four irrigation treatments on grain yield of four barley cultivars at two locations in Northern Jordan. Four barley cultivars (ACSAD176, Rum, Athrouh, and Yarmouk) were exposed to four irrigation treatments: 1) Full irrigation using treated wastewater (FWW); 2) Supplementary irrigation using treated wastewater (SWW); 3) Supplementary irrigation using fresh water (SFW); 4) Rainfed treatment without irrigation (RF). Plants exposed to full irrigation treatment using treated wastewater had higher grain yield than plants exposed to SFW and RF treatments for all cultivars. The full irrigation treatment using wastewater (FWW) increased grain yield in comparison with the supplementary irrigation treatment using wastewater (SWW) for ACSAD176 and Rum, but the difference was not significant for Athrouh and Yarmouk. Grain yield of plants exposed to supplementary irrigation using wastewater was higher than those plants exposed to supplementary irrigation using fresh water. The supplementary irrigation treatments increased grain yield in comparison with the RF treatment. For FWW and SWW treatments, Rum had the highest grain yield than other cultivars. ACSAD176 had higher yield than Athrouh for FWW and SWW. ACSAD176 did not differ in grain yield from Yarmouk for all treatments except for FWW, where ACSAD176 had higher grain yield. Athrouh and Yarmouk did not differ in grain yield for all treatments. The grain yield of all cultivars was higher at Ramtha location than at JUST. Rum had the highest yield and Athrouh had the lowest yield at Ramtha. At JUST, Rum and ACSAD176 had the highest yield. In conclusion, full or supplementary irrigation using treated wastewater increased grain yield for all cultivars and Rum had the highest yield among cultivars at various conditions.