Changes of maize lodging resistance after physiological maturity and its influencing factors in Sichuan
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摘要: 玉米茎秆强度下降是造成生理成熟后玉米倒伏的重要因素。为明确玉米生理成熟后茎秆强度变化及影响因素, 本试验以玉米品种‘正红6号’为材料, 设置不同密度处理, 通过研究其生理成熟后茎秆强度、单位长度干重、含水率等变化规律, 分析影响生理成熟后茎秆强度的关键因素, 为机械粒收技术推广提供科学指导。结果表明, 玉米生理成熟后节间茎秆强度逐渐下降, 随着时间推移, 降低幅度逐渐减小; 生理成熟后玉米茎秆单位长度干重、含水率逐渐降低, 节间长粗比略有增加。不同密度间茎秆强度差异显著, 生理成熟后茎秆强度下降幅度不同, 在4.5万~10.5万株∙hm−2密度范围内, 随着密度增加, 茎秆强度下降幅度呈降低趋势, 低密度茎秆强度下降幅度大于高密度处理。种植密度增加导致玉米茎秆单位长度干重显著降低, 节间长粗比显著增加。本研究发现玉米生理成熟后茎秆单位长度干重降低是茎秆强度降低的主要原因; 种植密度增加显著降低了茎秆强度, 同时随着站秆时间的延长, 茎秆强度进一步降低, 增加了玉米倒伏风险。因此, 合理密植、适期收获能降低因生理成熟后站秆能力下降而导致倒伏的风险。
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关键词:
- 玉米 /
- 生理成熟；茎秆含水率 /
- 单位长度干重 /
- 茎秆强度 /
- 抗倒性能
Abstract: Densification planting and delayed harvesting are important measures for the promotion and development of mechanized grain harvesting technology of maize, but they also reduce the lodging resistance of stalks and increase the risk of lodging. The appearance of maize lodging not only increases the difficulty of mechanical harvesting and reduces the speed of mechanical harvesting, but also increases the loss of ear caused by lodging and reduces the yield of mechanical grain harvest. Therefore, the purpose of this experiment was to explore the changing law of the lodging resistance ability of maize stalks after physiological maturity under different densities and to provide a scientific basis for the development of maize dense planting and high-yielding mechanical grain harvest technology. This experiment used ‘Zhenghong 6’ as the material and set 6 density treatments: 3.0×104 plants∙hm−2 (B1), 4.5×104 plants∙hm−2 (B2), 6.0×104 plants∙hm−2 (B3), 7.5×104 plants∙hm−2 (B4), 9.0×104 plants∙hm−2 (B5), and 10.5×104 plants∙hm−2 (B6). In the physiological maturity period (August 6, A1), 11 d after physiological maturity (August 17, A2), 22 d after physiological maturity (August 28, A3), and 35 d after physiological maturity (September 10, A4), 5 plants in each plot were sampled and the changing laws of stalk strength, internode morphology, internode dry matter, moisture content, etc. were determined. The results showed that the internode stalk strength of maize decreased after physiological maturity, but the decreasing range gradually reduced with time. After physiological maturity, the dry weight per unit length and water content of stalk decreased, while the internode length-to-diameter ratio increased slightly. Stalk strength and it’s change with time were significantly different among different densities after physiological maturation. In the density range of 4.5×104 plants∙hm−2 to 10.5×104 plants∙hm−2, the decreased amplitude of stalk strength showed a decreasing trend with the increase of density, and that of stalk strength of low density was greater than that of high density. The increase in planting density resulted in a significant decrease in stalk dry weight per unit length and a significant increase in the internode length-to-diameter ratio. The results showed that the decrease of stalk dry weight per unit length after physiological maturity was the main reason for the decrease of stalk strength. The increase of planting density significantly reduced the stalk strength, and with the extension of standing time, the stalk strength further decreased. The stalk strength of different densities decreased differently, and the decrease rate of low density was greater, but the stalk strength of high density was still lower than that of low density treatment all the time. Therefore, properly dense planting and harvest at the right time can reduce the risk of lodging caused by the decline of the standing capacity of culms after physiological maturity of maize. -
图 1 研究区玉米取样期间部分气象资料
Figure 1. Partial meteorological data during the sampling period of maize in the study area
图 2 玉米生理成熟后不同时间不同茎秆节间的单位长度干重变化
S3、S4和SX分别为基部第3、第4节间和穗下第1节间。箱线图中箱体部分代表50%样本的分布区域, 即四分位区间(IQR)。两端线为Tukey法判定的合理观测样本边界。箱体中实线为样本中位数, 实心点为样本均值, 空心点表示异常值。图中不同小写字母表示不同取样期在P<0.05水平差异显著。S3 and S4 are the third and fourth internodes from the stem base; and SX is the first internode below the ear. The main box called IQR contains fifty percent samples in Box-whisker Plot. The two sidelines mean the reasonable sample borders in Tukey method. The solid line in box positions the median sample. The solid point sthands for the average. The circle stands for the outlier. Different lowercase letters indicate significant differences at P<0.05 among different sampling dates.
Figure 2. Changes in dry weight per unit length of different maize internodes in different times after physiological maturity
图 3 不同密度玉米不同茎秆节间的单位长度干重变化
S3、S4和SX分别为基部第3、第4节间和穗下第1节间。箱线图中箱体部分代表50%样本的分布区域, 即四分位区间(IQR)。两端线为Tukey法判定的合理观测样本边界。箱体中实线为样本中位数, 实心点为样本均值, 空心点表示异常值。图中不同小写字母分别表示不同密度在P<0.05水平差异显著。S3 and S4 are the third and fourth internodes from the stem base; and SX is the first internode below the ear. The main box called IQR contains fifty percent samples in Box-whisker Plot. The two sidelines mean the reasonable sample borders in Tukey method. The solid line in box positions the median sample. The solid point stands for the average. The circle stands for the outlier. Different lowercase letters indicate significant differences at P<0.05 among different densities.
Figure 3. Changes in dry weight per unit length of different maize internodes with different densities
图 4 玉米生理成熟后不同时间(月-日)不同茎秆节间含水率变化
S3、S4和SX分别为基部第3、第4节间和穗下第1节间。图中不同小写字母分别表示不同取样期在P<0.05水平下差异显著。S3 and S4 are the third and fourth internodes from the stem base; and SX is the first internode below the ear. Different lowercase letters indicate significant differences at P<0.05 among different sampling dates.
Figure 4. Changes in moisture content of different maize internodes in different times (month-day) after physiological maturity
图 5 玉米生理成熟后不同时间不同茎秆节间的长粗比变化
S3、S4和SX分别为基部第3、第4节间和穗下第1节间。箱线图中箱体部分代表50%样本的分布区域, 即四分位区间(IQR)。两端线为Tukey法判定的合理观测样本边界。箱体中实线为样本中位数, 实心点为样本均值, 空心点表示异常值。图中不同小写字母分别表示不同取样期在P<0.05水平差异显著。S3 and S4 are the third and fourth internodes from the stem base; and SX is the first internode below the ear. The main box called IQR contains fifty percent samples in Box-whisker Plot. The two sidelines mean the reasonable sample borders in Tukey method. The solid line in box positions the median sample. The solid point stands for the average. The circle stands for the outlier. Different lowercase letters indicate significant differences at P<0.05 among different sampling dates.
Figure 5. Changes in length/diameter ratio of different maize internodes in different times after physiological maturity
图 6 不同密度玉米不同茎秆节间的长粗比变化
S3、S4和SX分别为基部第3、第4节间和穗下第1节间。箱线图中箱体部分代表50%样本的分布区域, 即四分位区间(IQR)。两端线为Tukey法判定的合理观测样本边界。箱体中实线为样本中位数, 实心点为样本均值, 空心点表示异常值。图中不同小写字母表示不同密度在P<0.05水平差异显著。S3 and S4 are the third and fourth internodes from the stem base; and SX is the first internode below the ear. The main box called IQR contains fifty percent samples in Box-whisker Plot. The two sidelines mean the reasonable sample borders in Tukey method. The solid line in box positions the median sample. The solid point stands for the average. The circle stands for the outlier. Different lowercase letters indicate significant differences at P<0.05 among different densities.
Figure 6. Changes in length/diameter ratio of different maize internodes with different densities
表 1 不同密度玉米生理成熟后不同时间不同节间茎秆强度
Table 1. Strength of basal internodes of maize with different densities after physiological maturity
取样日期(月-日)
Sampling date (month-day)密度 Density
(×104 plants∙hm−2)穿刺强度
Rind penetration strength (N)弯曲强度
Bending strength (N)S3 SX S4 SX 08-06 (生理成熟期
Physiological maturity date)3.0 57.80±5.0ab 32.50±2.6a 310.04±55.4b 128.56±10.5a 4.5 63.24±4.0a 29.64±1.8a 360.62±68.7a 135.72±13.5a 6.0 50.24±7.1bc 28.12±2.4a 222.66±55.8c 83.82±15.8b 7.5 44.76±4.8c 22.04±1.8b 139.18±33.8d 53.76±12.0cd 9.0 44.12±1.9c 22.80±3.7b 123.38±7.1de 69.92±23.0bc 10.5 33.72±4.5d 22.68±2.6b 84.32±11.7e 42.53±8.0d 平均 Average 48.98±10.7a 26.30±4.7a 206.70±110.6a 85.72±38.0a 08-17 3.0 54.98±7.5a 22.12±4.4a 279.58±63.2a 91.64±17.5a 4.5 47.98±5.3a 22.32±3.1a 211.12±28.7b 79.76±16.5a 6.0 54.36±8.2a 24.26±3.7a 202.16±69.5b 73.34±15.2a 7.5 37.76±13.0b 22.76±3.5a 103.28±26.6c 49.58±13.1b 9.0 35.28±4.0b 22.20±4.9a 113.86±19.7c 50.42±15.3b 10.5 37.70±7.2b 21.94±4.3a 111.76±28.8c 51.50±9.1b 平均 Average 44.68±11.0b 22.60±3.7b 170.29±77.7b 66.04±21.4b 08-28 3.0 56.48±5.3a 20.26±2.5ab 246.58±22.6a 59.33±3.6a 4.5 49.30±5.2a 18.90±3.0abc 175.44±41.0b 72.53±10.2a 6.0 37.78±5.2b 21.12±4.6a 96.36±31.5c 37.86±13.7b 7.5 32.08±5.8bc 16.50±2.5abc 64.16±16.6c 28.83±7.8b 9.0 30.44±7.3bc 16.15±4.0bc 71.60±15.0c 38.32±12.2b 10.5 24.72±2.0c 15.12±4.7c 65.12±12.4c 31.88±6.8b 平均 Average 38.47±12.3c 18.01±4.0c 119.88±73.3c 44.79±18.0d 09-10 3.0 57.88±9.5a 23.30±6.5a 201.48±43.8a 98.40±31.4a 4.5 33.70±4.1bc 17.88±1.8bc 83.06±22.8bc 44.20±12.8c 6.0 40.72±6.6b 18.60±3.6bc 120.04±21.2b 63.10±9.4b 7.5 29.16±5.7c 19.08±1.5ab 71.30±17.8bc 35.32±12.1c 9.0 31.64±11.0c 15.30±2.1bc 82.38±9.7bc 43.96±6.8c 10.5 27.86±2.7c 13.94±2.6c 58.00±5.2c 33.50±6.4c 平均 Average 36.83±12.3c 18.01±4.4c 102.71±53.3c 53.08±26.9c F 取样日期 Sampling date (A) 24.504** 39.723** 51.819** 49.696** 密度 Density (B) 49.279** 9.479** 79.988** 52.675** A×B 3.570** 1.865* 6.197** 6.067** S3、S4和SX分别为基部第3、第4节间和穗下第1节间。表中不同小写字母表示同一取样时期不同密度在P<0.05水平差异显著, 平均值后的不同小写字母表示不同取样时期在P<0.05水平差异显著。*表示P<0.05水平影响显著, **表示P<0.01水平影响显著。S3 and S4 are the third and fourth internodes from the stem base; and SX is the first internode below the ear. Different lowercase letters in the table indicate significant differences among different densities at P<0.05 in the same sampling date. Different lowercase letters after the averages indicate significant differences at P<0.05 among different sampling dates. * and ** indicate significant effects at P<0.05 and P<0.01 levels, respectively. 
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表 2 玉米不同密度下不同节间茎秆强度与生理成熟后站秆时间的拟合参数及结果
Table 2. Fitting parameters and results of stalk strength of different internodes and stalk standing time after physiological maturation in maize under different densities
密度 Density
(×104 plants∙hm−2)穿刺强度 Rind penetration strength (N) 弯曲强度 Bending strength (N) S3 SX S4 SX b R2 b R2 b R2 b R2 3.0 0.0199 0.0015 −0.2395 0.2551* −3.1807 0.4601** −0.9407 0.1711 4.5 −0.7728 0.7540** −0.3340 0.6796** −7.6035 0.8023** −2.4597 0.7793** 6.0 −0.3963 0.3023* −0.2780 0.5279** −3.5791 0.4353** −0.8125 0.2392* 7.5 −0.4579 0.3855** −0.1301 0.2460* −2.0864 0.5084** −0.6393 0.3311** 9.0 −0.3609 0.3098* −0.2484 0.4481* −1.4268 0.5345** −0.7632 0.2791* 10.5 −0.2679 0.2720* −0.2936 0.5085** −1.1392 0.3140* −0.4318 0.2730* *和**分别表示在P<0.05和P<0.01水平相关显著。* and ** indicate significant correlations at P<0.05 and P<0.01 levels, respectively.
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表 3 生理成熟后玉米茎秆强度与茎秆性状的相关性
Table 3. Correlation between stalk strength and stalk traits of maize after physiological maturity
指标
Index穿刺强度
Rind penetration strength含水率
Moisture content单位长度干重
Dry weight per unit length长粗比
Length/diameter ratio弯曲强度 Bending strength 0.503* 0.968** −0.767** 含水率 Moisture content 0.489* 0.438* −0.329 单位长度干重 Dry weight per unit length 0.934** 0.385 −0.797** 长粗比 Length/diameter ratio −0.867** −0.432* −0.812** 表格左下角数据为第3节间穿刺强度与茎秆性状的相关性, 右上角为第4节间弯曲强度与茎秆性状的相关性。*和**分别表示P<0.05和P<0.01水平相关显著。The data in the lower left corner of the table is the correlation coefficients between the rind penetration strength of the third internode and the stem traits; the data in the upper right corner is the correlation coefficients between the bending strength of the fourth internode and the stem traits. * and ** mean significant correlation at P<0.05 and P<0.01 levels, respectively.
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