Integrated effects of genotype, sowing date, and plant density on wheat grain yield

Wheat yields in production often fall below the genetic potential of varieties, creating a persistent challenge in improving productivity. This study investigated the effects of genotype, sowing date, sowing density, and fertilization model on wheat yield, as well as their interactions, to identify optimal management strategies. Field trials were conducted during two successive growing seasons in the Semberija region, Republic of Srpska, Bosnia and Herzegovina, using three wheat varieties. The experiment followed a randomized split-plot design with three replications, including three varieties, three sowing dates, five sowing densities, and three fertilization models. Data were analyzed with four-factor ANOVA, and significant differences were tested using Fisher’s LSD at the 0.05 and 0.01 probability levels. The results showed that average yields exceeded 8,000 kg ha⁻¹ in the first year, but decreased with delayed sowing. Yield losses due to late sowing could not be offset by increasing seed density, although 400-500 seeds m⁻² proved optimal. Fertilization effects varied across conditions, with the second fertilization model producing the highest yields under favorable circumstances. Overall, both individual treatments and their interactions significantly affected yield, underscoring the importance of tailoring sowing and fertilization practices to specific varieties and environments.