冗余器官去除对高产夏玉米产量形成的影响

Effects of Removing Redundant Organs on Yield Formation of High-yielding Summer Maize

针对高产夏玉米进一步提高产量存在的“群体数量”和“个体质量”的现实矛盾，于2013－2014年度采用大田试验，以常规种植为对照，研究了不同冗余器官去除对夏玉米产量和光合特性的影响，旨在探索在“群体数量”的基础上进一步提高“个体质量”的方法。结果表明，去除雄穗和下部叶片提高了玉米穗位叶净光合速率和最大籽粒灌浆速率，促进了营养器官干物质向籽粒的转移，千粒质量显著提高。去除雄穗可改善冠层光照条件，去除下部叶片可以延长植株活跃灌浆时间和降低田间耗水量，在缺水年份还可以减缓水分胁迫的负面作用。去除雄穗、去除下部叶片和去雄去叶等3个去冗余处理丰水年可使产量分别提高12．3％，2．6％，3．0％；缺水年去叶、去雄去叶的产量分别提高6．1％和8．8％，去除雄穗则不能增产。去除冗余叶片较常规对照耗水量减少34．5～42．5 mm，水分利用效率提高14．3％～17．2％。在玉米生产中，去除雄穗或下部叶片可以作为高产条件下进一步提高夏玉米产量的一种方法。

In the light of the actual conflict between populationand individual qualityon increasing the maize yield,during summer maize seasons from 201 3 to 201 4 （June -early October）a field experiment was con-ducted to study the effects of removing redundant organs on yield and photosynthesis of high-yielding summer maize,and the objectives of this study was to search out a new method to harmonize the relationship between maizepopulationand individual quality,conventional maize planting as control.The results showed that removing tassel and lower leaves increased the net photosynthetic rate and maximum grain-filling rate,and promoted matter transport from vegetative organs to grains.Tassel removal could improve light distribution in canopy.Lower leaves removal may prolong grain-filling period and decrease water consumption or relief water-stress in dry year.Compared with the control,in 201 3（rainy year）tassel removal,leaves removal and tassel ＆amp;leaves removal could increase grain yield by 1 2.3%,2.6% and 3.0% respectively;in 201 4 （dry year）leaves removal and tassel ＆amp;leaves removal in-creased yield by 6.1 % and 8.8%,but tassel removal had no effect on yield.Furthermore,with redundant leaves re-moval the water consumption was decreased by 34.5 -42.5 mm,water use efficiency was increased by 1 4.3% -1 7.2% compared with the control.So tassel removal and lower leaves removal should be regarded as a new method to further increase grain yield of high-yielding summer maize.