不同穗型春玉米干物质生产和籽粒灌浆对种植密度的响应
以中单909(ZD909)、吉单209(JD209)和内单4号(ND4)为材料,设置4.50、6.75、9.00、11.25和13.50万株hm-2等5个种植密度,于2013~2014年研究了不同种植密度下春玉米籽粒产量、干物质积累和灌浆特性的响应特征及其品种差异。结果表明,3个品种的籽粒产量均随种植密度提高呈先增加后下降趋势,中小穗型品种ZD909在各密度下的产量均高于大穗型品种JD209和ND4。ZD909在9.00万株hm-2下达到最高产量(13.7 ×103 kg hm-2), JD209和ND4在6.75万株hm-2下达到最高产量,分别为11.7和10.2 ×103 kg hm-2。群体干物质积累量随密度增加而显著提高,但收获指数呈下降趋势。随密度的提高,ZD909的干物质递增幅度高于JD209和ND4,收获指数下降幅度小于后两个品种。籽粒最大灌浆速率、灌浆持续时间均随种植密度的增大而减小,其中ZD909灌浆持续期、活跃灌浆期均显著长于JD209和ND4。上述结果表明,中小穗型春玉米品种的生产力受密度的不利影响程度显著低于大穗型品种,表现出更强的密度适应能力,密植增产潜力大。
英文摘要:
In order to learn the differences in biomass production and grain filling to planting density between spring maize cultivars, a two-year field experiment was conducted with three cultivars (Zhongdan 909: ZD909; Jidan 209: JD209; Neidan 4: ND4) under five planting densities (4.50, 6.75, 9.00, 11.25 and 13.50 plant ha-1) in 2013-2014. The experiment was implemented in Gongzhuling experimental station, Jilin Province, China. The results showed that grain yields firstly increased to the highest values and then declined significantly with the increase in planting density. As comparison with the large ear type cultivars of JD909 and ND4, higher grain yields were found under all planting densities of in the medium ear type cultivar of ZD909. ZD909 got the highest yield (13.7 ×103 kg ha-1) under the planting density of 9.00×104 plant ha-1, while the JD909 and ND4 got their highest yields under the planting density of 9.0×104 plant ha-1 by 11.7 and 10.2 ×103 kg ha-1, respectively. Along with planting density increasing, plant population dry matter accumulation increased significantly, however, harvest index (HI) decreased significantly. Population dry matter accumulation and HI for ZD909 were higher than those of JD209 and ND4 under dense planting. The maximum grain-filling rate and duration declined along with the planting density increasing, and higher maximum grain-filling rate and duration were found in ZD909 than JD909 and ND4. The above results indicate that the negative impacts of dense planting on maize yielding functions were lower for the medium ear type cultivar than the large ear type cultivar, suggesting greater adaptability to dense planting and a higher yielding potential.
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