不同去根处理对夏玉米根系形态及产量的影响

以玉米杂交种郑单958为材料,研究在7.5万株/hm~2条件下大喇叭口期、吐丝期去根处理对植株根系形态及产量的影响。结果表明,吐丝期去根处理的植株穗粒数、千粒重和产量较不去根处理的植株分别提高8.70%、4.74%和1.98%;大喇叭口期去根处理的植侏分别降低16.53%、10.29%和2.74%。吐丝期去根处理的植株地上部总干物重和分配至果穗中的干物质比例最高,较对照分别增加0.72%和4.96%。两种去根处理显著增加0~10 cm土层内的根系长度,尤其增加0.5~1.0 mm毛细根的数量,利于对耕层水分和营养的吸收。大喇叭口期去根处理增加各土层内的根系表面积和根体积,吐丝期去根处理增加0~10 cm土层内的根系表面积和根体积。密植高产玉米群体存在根系冗余,在玉米吐丝期适当去根处理对玉米产量的提高具有促进作用。

Effects of Different Root-cutting Treatments on Root Morphology, Dry Matter Accumulation and Yield of Summer Maize

The effects of different root-cutting treatments on root morphology and grain yield were studied by using maize hybrid Zhengdan958 as material under planting density of 75 000 plants/ha in the field. The treatment was done in large bell shaped stage(DR) and silking stage(TR), respectively. The results showed that, compared with CK, the grain number, 1 000-grain weight and yield of TR treatment were improved by 8.70%, 4.74% and 1.98%, respectively, in terms of DR treatment,they were reduced by 16.53%, 10.29% and 2.74%, respectively. With the advance of growth, dry matter weight of the whole plant above ground and partitioning rate to ears were gradually improved of TR treatment, they were 0.72% and 4.96% higher than CK, respectively. The root length in 0 to10 cm soil layer and amount of roothair between 0.5-1.0 mm in diameter were improved, which is conducive to absorb water and nutrients.The root surface area and volume in each soil layer were significantly improved by DR treatment, while, they were improved only in 0-10 cm soil layer of TR treatment. It can be deduced from the study that root redundancy exists in high-density and high-yielding maize population, the yield could be improved by proper root-cutting treatment at silking stage.