Quantitative and Qualitative Evaluation of Spring Bread Wheat (Triticum aestivum L.) Cultivars under Different Planting Dates

In order to evaluate the quantitative and qualitative performance of spring bread wheat cultivars under different planting dates, an experiment was conducted in Gonbad Agricultural Research Station, Gonbad, Golestan province, Iran, during two cropping seasons (2020-2022) as split plot based on randomized complete block design (RCBD) with four replications. Seven planting dates (1 November, 11 November, 21 November, 1 December, 11 December, 21 December and 31 December) were placed in main plots and four bread wheat genotypes (Araz, Arman, Taktaz and N-93-9) were placed in subplots. The delayed planting led to a significant decrease in the length of the phenological stages and the grain filling period. The highest grain yield was obtained from the planting at 11 November (5813 kg ha-1), which was not significantly different from grain yield in 21 November (5788 kg ha-1) and 31 November (5641 kg ha-1) planting dates. In most of the agronomic traits, the delayed planting dates (21 December and 31 December) had significantly lower values than planting in 11 November, 21 November and 1 December. Mean comparison for interaction effect of planting date×cultivar showed that planting Arman cultivar in 11 November, Araz cultivar in 11 November, 21 November and 1 December, Arman cultivar in the 21 November and Taktaz cultivar in the 21 November led to the highest grain yield. In the three delayed planting dates (11 December, 21 December and 31 December), the grain yield of Taktaz and Araz cultivars was higher than other genotypes. Mean comparisons on the traits related to bread-making quality showed that the two delayed planting dates (21 December and 31 December) had higher values in terms of protein and wet gluten content, compared to the two early planting dates (1 November and 11 November). Taktaz cultivar had the highest bread-making quality, particularly because it indicated the highest protein and wet gluten content.