播期对春玉米生长发育与产量形成的影响
Effect of sowing date on growth and yield of spring-maize
-
摘要: 以“郑单958”和“鲁单984”为材料, 比较研究了两个播期(4月24日和5月15日)条件下春玉米的生长发育和产量形成, 探讨了春玉米生长发育与气候条件的关系。结果表明, 不同播期的春玉米生长发育和产量都存在显著差异。与4月24日播期相比, 5月15日播期的春玉米产量(干重)提高2 157 kg·hm-2(郑单958)和1 137 kg·hm-2(鲁单984)。粒重在播期间、品种间及播期与品种互作间差异均不显著。穗粒数在品种间不显著, 但在播期间差异达显著水平, 第2个播期穗粒数提高幅度达37.8%(郑单958)和11.2%(鲁单984)。通过对不同播期间气象因子的分析发现, 降雨是影响华北平原春玉米生长发育和产量形成的最重要气象因子。降雨主要通过对穗粒数的调节来影响产量。开花期降雨过多所带来的低温寡照影响玉米的受精授粉与结实; 拔节至大喇叭口期降雨通过调节叶面积大小影响作物干物质积累, 进而影响籽粒的发育情况。本试验中, 5月15日是春玉米获得高产的最佳播期。合理安排播期, 重视降雨对春玉米生长发育及产量形成的影响, 是华北平原春玉米获得高产的重要措施。Abstract: Two sowing dates (April 24 and May 15) and two genotypes (“Zhengdan958” and “Ludan984”) were used to investigate the effect of meteorological change on the growth, development and yield of spring-maize. The results indicate significant differences in the growth and yield of spring-maize under different sowing dates. Yield of spring maize sown on May 15 increases by 2 157 kg·hm-2 for “Zhengdan958” and 1 137 kg·hm-2 for “Ludan984” than those sown on April 24. 1000-grain weight difference between two sowing dates and genotypes are insignificant. Difference in grain number per ear-corn is insignificant between the two genotypes, but significant between the two sowing dates. Grain number per ear-corn for spring-maize sown on May 15 increases by 37.8% in “Zhengdan 958”and 11.2% in “Ludan 984” over those sown on April 24. Kernel number decline constitutes the main reason for low grain yield in spring maize which is driven by climatic factors. Precipitation affects yield by decreasing kernel number. Low temperature and solar radiation, due to high precipitation during flowering, leads to low pollination, hence low kernel number. Also the lack of dry matter accumulation as a result of low precipitation during 6-to-12-leaf stage affects kernel development. Thus May 15 is a better sowing date for the high yield. Determining appropriate sowing date and reducing the negative effects of precipitation on yield are key factors for high yield spring-maize in North China Plain.