Introduction: Bread wheat (Triticum aestivum L.) is the most important crop in the world and is directly related to the nutrition of the global population. Bread wheat is considered a strategic crop worldwide due to the important role it plays in the political and economic arena of countries, especially developing countries. The economic importance of wheat, both in terms of production and nutrition, is greater than that of other agricultural products globally. Drought is one of the factors limiting growth in cereals, especially wheat. Drought stress has a significant impact on the early stages of wheat growth. Drought stress is one of the most important environmental stresses worldwide, which is the causes of reducing the production and productivity of agricultural products in arid and semi-arid regions. Based on limited water resources in the low-altitude region, optimal utilization and increased water productivity are absolutely essential for achieving the country's economic growth. Since the largest water consumption is in the agricultural sector, increasing water productivity is considered a fundamental strategy for achieving food security in the country.The most important indicator of water input consumption is the economic efficiency of water use in crops. From an economic perspective, only increasing water use efficiency is not enough, but the product produced must provide farmers with greater economic value. The aims of this research, are to examine the return of bread wheat lines and cultivars produced under normal and dry stress conditions in farmers fields located in villages in Nazarabad city of  Alborz province.
Materials and Methods: In terms of methodology, this research was conducted in the form of an agricultural experiment and inferential analysis, and  for data collection, it was carried out through observation and documentation To conduct on-farm studies of new bread wheat promising lines, three lines (M-99-9, M-99-15 and MDH-99-10) were selected from ERWYT (Elite Regional Wheat Yield Trial) under normal and terminal drought conditions for temperate climates and compared to one commercial varieties of Amin (as local check).The lines were sown on 2000 m² areas under both terminal drought and normal irrigation conditions in farmer’s fields of Kal Bahram and Mohsenabad villages in Nazarabad city of Alborz province during  2023-2024 research period. In this study, the terminal drought experiment, entailed cutting off irrigation at the booting stage, while irrigation continued in normal irrigation  treatment. Quality characteristics of the grain of bread wheat lines and the check were measured under both normal and terminal drought conditions in the target regions. For economic evaluation, this research used profitability indicators, including net income, gross margin, the safe return percentage and the accounting rate of return.Technical and economic productivity indices were used to assess the efficiency of water input consumption in crop production. The technical (or physical) productivity index is the ratio of the amount of product produced to the amount of water input consumed. The higher this index, the more efficient water consumption.Other indicators that include financial and economic aspects of productivity are the gross value of product produced per unit of water input and the net profit from product production per unit of water input.
Results and Discussion: According to the grain yield evaluation results, M-99-15 wheat line, with a grain yield of 12110 kg ha^-1 in normal irrigation experiment (Mohsen Abad village) and the MDH-99-10 line, with an average seed yield of 9470 kg ha^-1 under drought stress conditions, increased by 29 and 18 percent, respectively, compared to the check variety. In normal conditions, based on economic indicators, the total production costs, including land rent, were calculated for M-99-9, M-99-15, MDH- 99-10 lines, and the Shahed (Amin wheat cultivar) as 1347.6, 1351.2, 1348.6 and 1344.4 million rials per hectare, respectively.The net income from the production of M-99-15 was 768 million rials per hectare, which increased by 49.3, 30.6 and 157 percent compared to M-99-9, MDH- 99-10, and the control cultivar, respectively. The accounting rate of return (return on investment) for the production of, M-99-15, was 56.8 percent, which increased by 48.7, 30.3 and 155.8 percent compared to lines M-99-9, MDH- 99-10 and the control, respectively. Net income forom the production of bread wheat line M-99-15 was more than Amin variety by 257 percent and the cost per kg of this line was 111577 rials/kg, which was 22 percent lower than check. The cost per kilogram of product in line 99-15-M was estimated at 111,577 Rials, which was 13.5, 9.2, and 28.3 percent less than lines M-99-9, MDH- 99-10 and the control cultivar, respectively. In the production of the superior line M-99-15, the physical water productivity was estimated at 2.42 kg/m3 of water, and the economic water productivity was estimated 153,600 Rials profit/m3, higher than the control cultivar. Additionally, under terminal drought conditions, in Kal Bahram village, the total production costs, were 1313.5, 1312.5, 1315.7 and 1312.1 million rials per hectare for M-99-9, M-99-15, MDH- 99-10 lines and control cultivar as, respectively. The net income from the production of MDH- 99-10 was 341.5 million rials per hectare, which increased by 76.8, 182.9, and 266.8 percent compared to M-99-9, M-99-15 and the control ], respectively. The accounting rate of return for the production of MDH- 99-10, M-99-9, M-99-15, and the control rose by 14.7, 9.2, 26, and 7.1 percent, respectively. The cost per kilogram of product was estimated at 152,555, 160,256, 138,933, and 163,400 rialt, respectively. The net income for the production of (MDH-99-10) was more than  the Amin variety by 366.8 percent and the per kg was  15 percentlower than check. In the production of the superior line MDH- 99-10, the physical water productivity was estimated at 16.3 kg/m3, and the economic water productivity was 113,833 rials profit/m3 of water, which was higher than the control cultivar.
Conclusion and Suggestions: Based on agronomy and economic indicators, it is recommended to cultivate the MDH-99-10 line ujder drought stress conditions and M-99-15 under normal conditions in the targeted regions.