The Effect of Sowing Date on the Yield and Quality Formation of Different Cultivars of Cotton under Machine-Picked Conditions in the Coastal Saline-alkali Area of Eastern Hebei Province,China

[Objective] The effects of sowing date on the yield and quality formation of two different cotton cultivars were studied under machine-picked conditions in the coastal saline-alkali area of Eastern Hebei Province, China to identify the optimal sowing date and harvest method to improve cotton yield and quality consistency. [Method] The experiments were conducted in the state-run Haixing farm in Hebei Province during 2017 with a cotton crop seeded in 2016. The hybrid cotton Jiza 2 and conventional cotton Shikang 126 were used in this experiment. Varieties were tested using three sowing dates: April 15 (B1), April 25 (B2), and May 5 (B3) as the main plot. Six harvest dates were also used as subplots in this experiment: September 10, September 20, September 30, October 10, October 20, and October 30. [Results] The lint yield of Jiza 2 was nearly 1 400 kg·hm^－2 when the sowing date was May 5. Conversely, the highest lint yield for Shikang 126 was obtained when the cotton was sown on April 25. The yield associated with different sowing times was mainly formed in September, with this month accounting for more than 75% of yield. The fiber quality was better in September than October. The fiber quality of Jiza 2 was improved with a delay inthe sowing date. The best fiber quality for Shikang 126 was obtained with the April 25 sowing date. There was a small difference between the micronaire, fiber length, and length uniformity with different September harvest times. The fiber quality index was optimized and the consistency of the micronaire, upper half mean length, and length uniformity were higher with Shikang 126 before September 20 when sown on April 25. [Conclusion] Comprehensive consideration of yield and quality index indicated that hybrid cotton Jiza 2 performed best when sown on May 5 and harvested for the first time at the end of September. The conventional cotton Shikang 126 should be sown around April 25 and harvested for the first time on the last ten-day of September.