Effect of cytokinin application on productivity parameters of bread wheat (Triticum aestivum L.) cultivars

Plant growth regulators (PGRs) play a crucial role in modulating crop growth and development, with cytokinin being one of the most significant hormones affecting yield parameters in cereals. Despite advancements in wheat breeding, a significant portion of genetic variation influencing yield remains untapped. Cytokinin regulates cell division, resource allocation, and grain-filling processes, yet its field applications remain underexplored. This study was carried out during the growing seasons of 2023-24 at Al Qasim-Green University, college of Agriculture, plant production research field, Iraq to investigate the effect of spraying the cytokinin on four winter wheat cultivars. Cytokinin application implemented at concentrations of (0, 50 and 100 mg/L) noted as (T1, T2, and T3). Cultivars as a second factor included (Iba99, Baghdad, Bohuth22 and Abu Ghraib). The treatments were applied at both the green-up and flowering stages. Baghdad cultivar treated with 100mg\L of cytokinin exceeds other cultivars in most characteristics of study, such as: average tillers number, 1000 kernel weight, number of grains per spike and grain yield. Future research should focus on optimizing cytokinin application rates and time to maximize these benefits in different environmental conditions and wheat cultivars.