摘要：Profitability assessment has prime importance for every crop husbandry practice and cultural operation. For this purpose, two field experiment was carried out to investigate the response of spring planted sunflower hybrids to different irrigation levels/schedules and foliar application of abscisic acid. Two studies were done at the Agronomic Research Farm, University of Agriculture, Faisalabad, Pakistan. In first study, three irrigation schedules viz. four irrigations (25 DAS, bud initiation, flower initiation and achene formation), three irrigations (25 DAS, flower initiation and achene formation) and three irrigations (25 DAS, bud initiation and achene formation) were used. Sunflower hybrid Hysun-33 was subjected to exogenous application of different concentrations (0, 5μm and 10μm) of ABA at bud initiation or at flower initiation. In second study, Three sunflower hybrids viz. DK-4040 (large stature), S-278 (medium stature) and SF-187 (short stature) were subjected to different irrigation regimes and ABA applications i.e., four irrigations; 25 Days after Sowing (DAS), at bud initiation, flower initiation and achene formation and with no ABA spray, three irrigations; 25 Days after Sowing (DAS), at flower initiation and achene formation and with no ABA spray, three irrigations; 25 Days after Sowing (DAS), at flower initiation and achene formation and with ABA spray at bud initiation, three irrigations; 25 Days after Sowing (DAS), at bud initiation and achene formation and with no ABA spray, three irrigations; (25 Days after Sowing (DAS), at bud initiation and achene formation and with ABA spray at flower initiation. In first study, It was observed that three irrigations (25 DAS, at flower initiation and at achene formation), when 5μM ABA was applied at bud initiation under drought resulted in more profitable as compared to exogenous application of same concentration of ABA at flower initiation. So, it is suggested that three irrigations (25 DAS, at flower initiation and at achene formation), with foliar spray of 5μM ABA should be applied at bud initiation under drought. In second study, the dominance and marginal analysis about sunflower hybrids revealed that maximum Marginal Rate of Return (MRR) in sunflower hybrids was observed in T1 (control). Drought stress at bud initiation or at flower initiation reduced marginal rate of return. ABA application to DK-4040 under drought at bud initiation showed more increase in MRR than SF-187 and S-278.
