Sowing Dates Effects and Varieties Comparison and Their Interaction on Yield and Yield Components of Wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) growth is directly affected by sowing dates. However, the yield of wheat in Afghanistan is significantly lower than the global standard. Several factors including fertilizers, sowing dates, seeds and cultivation methods, contribute to this low yield. The objective of this research was to address this critical issue by comparison of the effects of different sowing dates on wheat yield and its components under Kabul climatic conditions. The same experiment was conducted at two sites in 2020 using a randomized complete block design (RCBD) with three replications and twelve treatments. The varieties used were Darolaman-07 (V1), Mazar- 99 (V2), and Chunta-1 (V3) as factor one, and sowing dates of November 10th (S1), November 18th (S2), November 26th (S3), and December 4th (S4) as factor two. Growth and yield parameters measured and analyzed included plant height, number of leaves plant-1, total number of tillers plant-1, leaf area index (LAI), leaf nitrogen content (N), spike length, number of spikelets spike-1, number of grains spike-1, grain weight spike-1, thousand- grain-weight, days to maturity, number of spikes plant-1, biological yield, grain yield, straw yield, and harvest index. Sowing dates had significant effects on some wheat growth and yield parameters. Sowing on November 10th, 2020, resulted in the highest plant height and leaves number per plant compared to later sowing dates. There was a significant interaction between sowing date and variety at (P˂0.01) in both growth and yield parameters. ANOVA analysis highlighted significant differences among wheat varieties in spike length, grain weight spike-1, thousand grain-weight, and harvest index, with notable variations observed among different varieties. Based on the results, the longest duration to maturity and the highest grain yield were observed on sowing date of November 10, 2020.