中文摘要：

为了让湖北地区种植郑麦9023获得高产、稳产，试验设置了4个播期水平和3个密度水平，研究了播期和密度对郑麦9023旗叶光合特性、干物质积累和产量及其构成因素的影响。结果表明，早播（10月11日）时成穗数减少，产量降低；适播（10月24日）时，旗叶干重较大，成穗数最多，产量最高；晚播（11月10日、11月24日）时，播期越迟，旗叶叶绿素含量由孕穗期到开花期上升幅度越大，千粒重增加，但成穗数急剧越少．产量显著降低．且加剧了赤霉病和穗发芽现象的发生。适宜的种植密度因播期而异：早播和适播时，密度加大．产量增加；晚播时，密度加大，产量先增加后减少。播期对产量及其构成因素的影响大于密度．适播配以适宜的种植密度是发挥郑麦9023高产潜力的基本条件。产量三因素对郑麦9023产量效应为成穗数〉穗粒数〉千粒重．维持地上部干物质积累量13．50t／hm^2左右、保持成穗数460万～490万／hm^2是郑麦9023在湖北地区获得高产的关键。相应的适宜播期为11月24日到11月初，适宜的种植密度为300万。375万／hm^2。

英文摘要：

In order to increase the yield of wheat cuhivar, Zhengmai 9023 in Hubei Province, the effects of sowing dates and planting densities on photosynthetic characteristics of flag leaf, dry biomass accumulation, grain yield and yield compo- nents were investigated. The results indicated that the average yield sown at October 11 decreased with the reduction of ears .Of all sowing dates, the average yield and final ear number sown at October 24 was the highest, besides, dry biomass ac- cumulation of boot leaf was high. The average yield and final ear number sown at November 10 and 24 decreased by a large margin with the delay of sowing date. However, chlorophyll content of boot leaf increase faster from booting to flowering stage with the delay of sowing date. The most suitable planting density changes with sowing dates. The average yield sown at Octo- ber 11 and 24 increased with enhancement of planting density. While the average yield sown at November 10 and 24 first increased and then decreased with enhancement of planting density. The influence of sowing date on grain yield components was bigger than that of planting density. Ears had the greatest impact on grain yield, followed by grains per ear and 1000- grain weight. In order to gain high yield of wheat Zhengmai 9023 in Hubei Province, it was key to keep dry biomass accu- mulation and final ears per hectare around 13.50t and 4 600-4 900 thousand per hectare, while the responding suitable sow- ing date respectively was from October to early November and planting density was 3 000-3 750 thousand seedlings per hectare.