Response of growth and yield of several sorghum varieties to plant density

The research was conducted in a farmer's field in Ramadi city, Anbar Governorate, during the spring and fall seasons of 2024 using a Randomized Complete Block Design (RCBD) with four replications and a split-plot arrangement, four genotypes of sorghum were used: “Rabeh,” “Kafer,” “Giza 113,” and “Inqath,” under three plant densities: 57.14 thousand plants ha-1, 71.43 thousand plants ha-1 and 95.24 thousand plants ha-1. Yield characteristics and components of sorghum were studied in terms of performance and variations. The results showed significant differences between varieties and plant densities, as the “Rescue” genotype was superior in grain yield, as the yield reached 6.37 Mgh-1 in the spring season and 7.67 Mgh-1 in the fall season. The “Inqath” variety also excelled in the number of grains per head, as it gave 2552 grains in the spring season and 2801.3 grains in the autumn season. Plant density had a significant effect on most traits in both the spring and fall seasons, while the interaction between plant density and genetic composition was significant in most of the traits studied. We conclude from this that most of the yield components in sorghum are more influenced by genetic factors. Therefore, the number of grains per head and grain weight can be relied upon as the main criteria in evaluating the grain yield of this crop. These characteristics accurately reflect the response of different varieties to environmental conditions and the interactions between them and plant density.