播期、收获期对玉米生长发育及冠层性状的调控

采用均匀试验设计,研究6个播期配合6个收获期对郑单958和伟科702生长发育、株型结构和产量性状的影响,通过播期、收获期调控实现高产。结果表明,冀中地区6月12日前播种,玉米抽雄和吐丝持续时间更为集中,播期每推迟3 d,抽雄和吐丝日期后推1 d;继续推迟播期,抽雄和吐丝日期后推4~5 d。2014年6月12日播种处理吐丝期冠层温度最高,不利于玉米授粉;6月15日后播种穗位叶SPAD值降低,尤其是生育后期伟科702叶片SPAD值降低幅度较大。播期对株高、穗位高和基部茎粗影响较大,播期与收获期对产量及其构成影响均显著,穗粒数随播期推迟而降低,千粒重随生育期延长而提高。经回归分析得出,夏玉米每提早播种1 d,产量平均增加98.4 kg/hm2;每推迟收获1 d,平均增产103.3 kg/hm2。郑单958获得较高产量的播期、收获期最佳组合为6月6日至6月12日播种,10月4日至10日收获。

Effects of Planting and Harvest Date on Growth and Development and Canopy Traits of Summer Maize

The experiment with six planting date combining six harvest date of cultivar in the field having medi-um soil fertility was conducted, to study the effect of different planting and harvest date on growth and development, canopy traits and yield of summer maize. The objective to achieve high yield when early sowing and delayed harvest for different cultivars. The results showed that tasseling and silking date could be delayed by 1 day when the plant-ing date was delayed for three day if sowing before 12 June, and be delayed by 4-5 day if sowing after 12 June in the central part of Hebei. The tasseling and silking duration was obvious shortened when sowing before in June 12th compared with the treatments of delayed sowing date, and canopy temperature of silking stage is higher for sowing in June 12th, 2014, and the higher temperature is not conducive to the maize pollination. Ear leaf SPAD decreased when the sowing date postponed to June 15th, and value of SPAD is greatly reduced for Weike702 at late growth stage. The effects of sowing period on plant height, ear position height and basal stem diameter were obvious. Plant-ing and harvest date can strongly affect grain yields and yield components, and grain number per spike increased with the delayed sowing date, 1 000-grain weight was significantly higher for early sowing + late harvest treat-ments. Every early sowing for 1 days or delayed harvest 1 day, the average yield increased 98.4 kg/ha or increased 103.3 kg/ha. For achieved high yield, the optimum combination was in June 6th to June 12th sowing and in October 4th to October 10th harvest.