ROLE OF ABA APPLICATION TO IMPROVE SOME SUNFLOWER TRAITS UNDER WATER DEFICIT STRESS

A field study was conducted during two spring seasons 2012 and 2013 at the experimental farm of Field Crop Department. College of Agriculture. University of Baghdad. That was to study the effect of irrigation of and concentrations of abscisic acid (ABA) in some morphological characteristics sunflower Helianthus annuus L. using the design of RCBD with split plot arrangement at three replications. The main plots were irrigation treatments, the control treatment (irrigation 50% of the water available), 70 %, 50%, and 30% of the amount of control water treatment coded S-1, S-2, S-3 and S-4, while secondary plots was occupied concentrations of ABA (0, 2.5, 5 and 7.5) micromoles coded C-0, C-1, C-2 and C-3. Irrigation treatment 70% of the treatment (control) gave the average plant height was 128 cm and leaf area 0.45 m(2). plant(-1) and duration from planting to flowering to 50% 77.62 day the crop growth rate 12.80 g. m(-2). d(-1) and root dry weight 30.85 g. plant(-1) as average for two seasons, and did not differe significantly from the irrigation treatment (control) started gave higher average rate of 136 cm and 0.45 m2. plant(-1) and 78.41 days and 12.08 g. m(-2). d(-1) and 31.46 g. plant(-1) for average two seasons respectively, while the irrigation treatment gave 30% of the treatment measurement lowest average for all irrigation treatments. Outweigh the concentration of 7.5 micromoles significant highest average dry weight of the root of 28.81 g.(-1) plant and crop growth rate of 9.95 gm.m(-2). d(-1) on average for the two seasons and duration from planting to 50% flowering 76.83 the first day of the season only. Therefore, we recommend possibility of irrigation water by 70% of a need of the full irrigation (50% depletion of available water) without significant effect on some morphological traits, in addition to possibility treatment of sunflower plants with ABA to improvement capacity of water stress.