密度和施氮量对强筋小麦藁优2018产量和抗倒性的影响

为明确减量播种和减施氮肥对强筋小麦品种藁优2018茎秆质量和抗倒性的影响,采用双因素裂区试验,研究了种植密度(D210,210万株·hm-2;D330,330万株·hm-2;D450,450万株·hm-2)和施氮量(N0,0kg·hm-2;N120,120kg·hm-2;N240,240kg·hm-2)对小麦倒伏高发期茎秆形态的影响,以及抗倒伏指数与茎秆形态指标的相关性。结果表明,在籽粒形成期和蜡熟期,密度由D210增加至D330,小麦茎秆重心高度显著增加,基部节间充实度、秆壁厚度、茎秆机械强度和抗倒伏指数降低;茎秆重心高度以N0最小,N240最高;基部节间秆壁厚度在3个施氮量处理间差异不显著;茎秆充实度、茎秆机械强度和抗倒伏指数随施氮量增加呈降低趋势,但在乳熟期和蜡熟期N120和N240差异不显著。相关分析表明,基部第1节间抗倒伏指数与节间粗度、充实度和第1节间秆壁厚度呈极显著正相关,与第2节间秆壁厚度相关性不显著。逐步回归分析表明,种植密度对小麦抗倒性的影响大于施氮水平。籽粒产量在不同密度处理间差异性不显著,但在不同施氮量间表现为N120和N240处理显著高于N0处理。因此,210万株·hm-2至330万株·hm-2的种植密度和120kg·hm-2的氮素水平在获得较高产量的同时具有较强的抗倒伏能力,是本试验条件下小麦抗倒高产的最优组合。

Effect of Planting Density and Nitrogen Fertilization Rate on Lodging Resistance and Grain Yield of Strong Gluten Wheat Gaoyou 2018

In order to clarify the effects of reducing sowing and reducing nitrogen fertilization on stem quality and lodging resistance of strong gluten wheat and the correlations between lodging resistance index and morphological characters of stem in the test area, a split plot design was carried out, with planting density (including 2.1 million, 3.3 million, and 4.5 million plants per hectare) as main plot, and nitrogen fertilization rate (including 0 kg·hm^-2, 120 kg·hm^-2(N120), and 240 kg·hm^-2 (N240)) as split plots. The results showed that planting density (2.1 million, 3.3 million plants per hectare) significantly increased the height of gravity center,but decreased filling degree and wall thickness of basal internodes,stem mechanical strength and lodging resistance index during grain forming stage to ripening stage. Height of gravity center in N0 was the shortest, but was the tallest in N240 among the three nitrogen levels. It is insignificantly correlated with the wall thickness of the basal internodes among the three nitrogen levels. Higher nitrogen decreased filling degree of basal internodes,stem mechanical strength and lodging resistance index,the differences of which were insignificantly in nitrogen treatments (N120 and N240) during milking stage to ripening stage. Correlation analysis showed that the lodging resistance index of the 1st internode was significantly positively correlated with the diameter, filling degree of basal internodes and wall thickness of the 1st internode, but it was insignificantly correlated with the wall thickness of the 2nd internode. Stepwise regression analysis indicated that planting density had more important effects on lodging resistance than nitrogen application. The grain yield was not significantly different under different densities, but those under N120 and N240 treatments were significantly higher than that under N0 treatment among different nitrogen levels. [JP2]The model (plant density of 2.1 or 3.3 million plants per hectare and nitrogen application of 120 kg·hm^-2) is optimal for lodging resistance and yield components of Gaoyou 2018 under the conditions of this experiment.