种植密度对不同熟期玉米品种子粒含水率和产量的影响

2019～2020年以陕单 650(中熟)和东单 60(晚熟)为材料，设置 4个种植密度 6.0×10⁴、 7.5×10⁴、 9.0×10⁴和10.5×10⁴株/hm²，研究密度对玉米产量及子粒含水率的影响。结果表明，增密可以提高不同熟期玉米品种的产量，陕单 650在密度为 9.0×10⁴株/hm²时最优产量为 18 083.5 kg/hm²，东单 60在密度 7.5×10⁴株/hm²时最优产量为17 472.9 kg/hm²。两个品种粒重及子粒含水率随密度的增大而减小，陕单 650达到最大灌浆速率的天数、平均灌浆速率较东单 60均早 4 d和高 0.06 g/d；陕单 650和东单 60子粒平均脱水速率为 0.98%/d和 0.93%/d，陕单 650在生理成熟 4 d后子粒含水率迅速降至 25%。当密度为 9.0×104株/hm²时，陕单 650的叶片干物质转运率明显高于东单 60。通过适度增密提高产量、缩短生育期降低子粒水分的技术途径，协同实现陕西春玉米密植高产机械子粒收获生产。

Effect of Planting Density on Grain Moisture Content and Yield of Maize with Different Maturity Hybrids

From 2019 to 2020, Shaandan 650(medium maturity) and Dongdan 60(late maturity) were used as materials with four plant densities of 6.0×10⁴, 7.5×10⁴, 9.0×10⁴ and 10.5×10⁴ plants/ha were set to study the effects of density on maize yield and grain moisture content. The results showed that increasing density could increase the grain yield with different maturity maize hybrids, the optimized yield of Shaandan 650 was 18 083.49 kg/ha when the density was 9.0×10⁴ plants/ha, while that of Dongdan 60 was 17 472.9 kg/ha when the density was 7.5×10⁴ plants/ha. The grain weight and grain moisture content of the two hybrids decreased with the increase of density. Days of Shaandan 650 reaching the maximum grain filling rate and the average grain filling rate were 4 d earlier and 0.06 g/d higher than those of Dongdan 60. The average grain dehydration rate of Shaandan 650 and Dongdan 60 were 0.98%/d, and 0.93%/d, and the grain moisture content of Shaandan 650 decreased rapidly to 25% after 4d of physiological maturity. When the density was 9.0×10⁴ plants/ha, leaf and material transport rates of Shaandan 650 were significantly higher than that of Dongdan 60. Therefore, through the technical approach of moderate densification to increase grain yield and shorten the growth period to reduce grain moisture, Shaanxi spring maize dense planting and high-yield mechanical grain harvest production were realized.