摘要：

为研究播期对冬小麦产量及产量构成的影响,生长发育及株型结构对积温的响应特征,明确适应气候变化的小麦生育特点及合理株型结构。2017年秋至2019年夏在河北藁城进行大田试验,设置5个播期,9月25日、10月5日、10月15日、10月25日和11月4日。结果表明,10月5-15日播种,冬前≥0 ℃积温410~549 ℃,小麦产量较高,该条件下穗数较高,穗粒数适中;积温过高达733 ℃时,无效分蘖多,分蘖成穗率降低,穗数下降;积温低于279 ℃时,穗数和穗粒数均下降。提出高产稳产小麦冬前个体指标:单株主茎和分蘖数量2.3个,次生根数量2.5条,主茎叶片数4.1片,单棱期越冬。积温对小麦株型结构有明显影响,随播期推迟,旗叶变长、变宽、叶面积增加,倒3叶至倒5叶变窄、叶面积降低,基部茎粗增加,上部1~2节节间增长,下部3~5节节间缩短,株高显著降低。由产量和冬前积温的拟合方程得出,气候变暖背景下高产稳产小麦适期晚播期限为10月8-14日,该条件下冬前积温范围为433~541 ℃,植株冬前生长发育适中,旗叶较小、茎节较短,倒3~5叶较大、茎节稍长,株型结构合理。

关键词: 冬小麦, 播期, 产量, 生长发育, 株型结构

Abstract:

The effects of sowing date on the yield and yield components of winter wheat,and the response characteristics of growth and development and plant type structure to accumulated temperature were studied in order to clarify the growth characteristics and reasonable plant type structure of wheat adapting to climate change.From autumn 2017 to summer 2019,field trials were conducted in Gaocheng,Hebei Province.Five sowing dates were set,September 25,October 5,October 15,October 25 and November 4.The results showed that the yield of wheat was higher sown from October 5 to 15 than other treatments,and the accumulated temperature before winter was 410-549 ℃.When accumulated temperature before winter was suitable,spike number was high and grain number per spike was moderate.When the accumulated temperature was as high as 733 ℃,the number of invalid tillers was more,the effective tiller rate was lower,and spike number was lower.When the accumulated temperature was insufficient to 279 ℃,the spike number and grain number per spike decreased.Accumulated temperature had a significant effect on growth and development indicators.Under the condition of high and stable yield,the individual index of wheat before winter was put forward:the number of main stem and tillers per plant was 2.3,the number of secondary roots was 2.5,the number of leaves of main stem was 4.1,and the spike differentiation of over winter was single edge stage.The accumulated temperature had an obvious effect on the plant structure of wheat.Delay with sowing date,the flag leaf became longer and wider,the leaf area increased,and the leaf from the top third to the top fifth became narrower and the leaf area decreased.Delay with sowing date,stem diameter of the base increased,the stem length of the top first to top second increased and length of the top third to top fifth decreased,and plant height decreased significantly.According to the equation of yield and accumulated temperature before winter,it was recommended that the suitable sowing time of wheat was October 8 to 14 under high and stable yield conditions,and the accumulated temperature range before winter was 433-541 ℃.Under late sowing conditions,the plant type structure was more reasonable,the growth and development of the plant were moderate before winter,the flag leaf was smaller and its stem length was shorter,and the leaf from the top third to the top fifth from the top was larger and their stem was slightly longer.

Key words: Winter wheat, Sowing date, Yield, Growth and development, Plant type structure