اثر رقابت چاودار (Secale cereal L.) بر خصوصیات رشدی و عملکرد گندم (Triticum aestivum L.) تحت تنش شوری

A greenhouse factorial experiment was conducted using a randomized complete block design with three replications to assess the competitive effects of varying wheat–rye (Secale cereal L.) planting ratios under salinity stress on the growth and yield traits of wheat (Triticum aestivum L.). Treatments included four planting ratios (100:0, 75:25, 50:50, and 25:75) and four salinity levels (2, 4, 8, and 16 dS/m). Phenological and morphological traits were monitored throughout the experiment, and shoot, seed, and root yields were measured at physiological maturity. Increasing salinity levels significantly shortened the duration of wheat phenological development and reduced key growth parameters. Both rye competition and salinity stress had significant effects (P < 0.01) on plant height, leaf number, SPAD index, grains per spike, thousand grain weight, grain yield, biological yield, and shoot-to-root ratio. Under combined stress conditions, root weight and grain yield declined by up to 92.66% and 88.9%, respectively. Higher rye densities moderately reduced wheat height and root biomass, while slightly enhancing grain-related traits. Overall, salinity and interspecific competition with rye were identified as major limiting factors for wheat growth and yield performance.