Abstract:

Planting density and sowing date are important factors affecting the grain quality of winter wheat. In order to quantify the effects of planting density and sowing date on winter wheat grain quality， and build the simulation model of the effects of planting density and sowing date on winter wheat grain quality， a field experiment were carried out in the 2019—2020 and 2020—2021 growing seasons using winter wheat variey Jimai 44 under different planting density and sowing date levels. On the basis of experiment data collected in the 2019—2020 growing season， the influence of planting density and sowing date levels on winter wheat grain quality was analyzed. The results showed that the protein content， wet gluten content and the dough water absorption rate increased firstly and then decreased， and the flour yield decreased gradually， while the dough stability time decreased first and then increased with the increase of planting density during on sowing date at October 10^th. The quality index decreased first and then increased with the increase of planting density during on sowing date at October 20^th. The protein content， wet gluten content and dough water absorption rate increased firstly and then decreased， while the flour yield and dough stability time decreased first and then increased during on sowing date at October 30^th. The protein content and dough water absorption rate decreased firstly and then increased， while the wet gluten content and flour yield decreased and the dough stability time increased with the delay of sowing date. On that basis， the simulation model of the effect of planting density and sowing date on the grain quality of winter wheat was built by introducing the impact factors of protein content， wet gluten content， flour yield， water absorption rate and stability time. These models were validated with an independent dataset collected from 2020 to 2021. The results showed that all root mean squared error （RMSE）， mean absolute error （d_a）， and ratio of d_a to the mean observation （d_ap） indicated that the simulated values were consistent with the measured data. These models could be used to simulate the effects of planting density and sowing date levels on winter wheat grain quality.

Key words: winter wheat, planting density, sowing date, grain quality, simulated model

摘要：

种植密度和播期是影响冬小麦籽粒品质的2个重要因素，为量化种植密度和播期对冬小麦籽粒品质的影响，构建种植密度和播期对冬小麦籽粒品质影响的模拟模型，以济麦44为材料于2019—2020和2020—2021年度开展了种植密度和播期试验，分析了种植密度和播期对冬小麦籽粒主要品质参数的影响规律。结果表明，在10月10日播期内，随着种植密度增加，小麦粗蛋白含量、湿面筋含量和面团吸水率均先增大后减小，出粉率逐渐减小，而面团稳定时间先减小后增大；在10月20日播期内，随着种植密度增加，小麦各品质指标均先减小后增大；在10月30日播期内，小麦粗蛋白含量、湿面筋含量和面团吸水率均先增大后减小，而出粉率和面团稳定时间则先减小后增大；随着播期延迟，籽粒蛋白质含量和面团吸水率先减小后增大，湿面筋含量和出粉率逐渐减小，而面团稳定时间则逐渐增大。通过引入种植密度和播期影响因子，构建了种植密度和播期对冬小麦籽粒品质影响的模拟模型。经2020—2021年度冬小麦生长季试验数据检验，根均方差（RMSE）、绝对误差（d_a）和绝对误差（d_ap）占实测值比率均显示模拟值和实测值有较高的一致性，所建模型可较好地模拟种植密度和播期对冬小麦籽粒品质的影响。

关键词: 冬小麦, 种植密度, 播期, 品质, 模拟模型