| Wheat is an important cereal crop in Shandong Province. Wheat yield is mainly decided by its variety characteristics, and also affected by cultivation conditions. In this study, four wheat varieties of Jimai 22, Yannong 24, Yan 2415 and Zhouyuan 9369 were used to research the effect on yield and its components of different wheat varieties by different sowing dates and quantities to determine the optimum sowing dates and quantities for the four varieties. It was of importantly theoretical and practical significance to draw out potential of the wheat varieties. The coclusions of the study were presented as follows.1. In the condintion of low sowing quantity, wheat yield decreased with deley of sowing date. High yield of Jimai 22 and Yan 2415 was on October, 5, and October, 12 to 19 for that of Yannong 24, and sowing date hardly had effect on Zhouyuan 9369. High yield of Jimai 22 and Yan 2415 under moderate sowing quantity was on October, 5, and October, 12 for that of Yannong 24 and Zhouyuan 9369. In the condintion of high sowing quantity, high yield of Jimai 22, Yannong 24 and Zhouyuan 9369 was on October, 12, and October, 5 for that of Yan 2415.2. With deley of sowing date, the panicle number per unit area and thousand grain weight of the four varieties decreased, and the grain number per spike of Jimai 22, Yan 2415 and Zhouyuan 9369 went up. The four sowing dates hardly had effect on the yield of Yannong 24 and Zhouyuan 9369. The difference of panicle number per unit area among varieties produced by sowing date reached 26%, while under 14% for that of grain number per spike and yield. |