Akademik Veri Yönetim Sistemi
IRRIGATION SCIENCE, cilt.44, sa.1, ss.1-17, 2026 (Scopus)
Given the growing and urgent need for strategies to mitigate the negative effects of drought stress in arid and semi-arid regions, a field study was conducted to evaluate the effects of plant growth promoting bacteria (PGPB) treatments with recycled wastewater and fresh water on seed yield and water productivity of safflower (Carthamus tinctorius L.) under deficit irrigation levels in 2022 and 2023. In the study, 0% (I0 - rainfed), 25% (I25), 50% (I50), 75% (I75) and 100% (I100) of the evaporation values read from the Class A pan were selected as irrigation levels; Two irrigation waters of different quality were used: recycled wastewater (RW) and fresh water (FW). The PGPB treatments were applied at four frequencies: R0 (no inoculation, control), R1 (single application at sowing), R2 (two applications: at sowing and 10 days after sowing), and R3 (three applications: at sowing, 10 and 20 days after sowing). Evapotranspiration (ETa) values were similar in both water types. The highest plant height, stem diameter, head diameter, 1000 grain weight and seed yield (107.36 cm, 10.52 mm, 28.55 mm, 48.21 g and 173.10 kg da−1 ) were measured among RW conditions with I100-R3 treatment recorded. In all treatments, WUE and IWUE ranged between 0.27 and 0.56 kg m−3 and 0.46 and 1.77 kg m−3 , respectively, and it was observed that water stress, the number of bacterial treatments and RW treatments WUE and IWUE values increased in both years. Yield response factor (ky) is between 0.30 and 0.37 for RW treatments and 0.35–0.39 for FW treatments. Similar results were observed in ky values of RW and FW treatments. This state is considered more tolerant to water stress. Thus, RW and deficit irrigation treatments can successfully improve productivity by increasing water efficiency under conditions where water resources are limited. However, it was determined that PGPB applications reduced the seed yield loss caused by water stress in the plant.