冀东地区种植密度对小麦京冬8号抗倒伏能力和产量的影响

为明确冀东地区种植密度对冬小麦抗倒伏能力和产量的影响,于2011-2013年度以当地推广的冬小麦品种京冬8号为材料,设每公顷375万、525万、675万和825万株4个种植密度处理,分析了不同密度下小麦茎秆质量、抗倒伏指数和产量的差异.结果表明,密度增大使小麦基部第1节间增长,增加了基部节间长在茎长中所占的比例、株高和重心高度,导致茎秆变细,茎秆机械强度和抗倒伏指数降低.当密度达到每公顷675万株时,小麦出现倒伏,密度再增加,倒伏时间提前,倒伏程度增大.群体干物质积累量在生育前期随密度增加而增加,但大密度导致植株分蘖衰亡较多,降低生育后期干物质生产能力,至成熟时以每公顷525万株的干物质积累量和花前营养器官贮存干物质向籽粒的运转量最多.虽然每公顷675万株的有效穗数最多,但由于倒伏严重,其千粒重最轻,每公顷825万株的有效穗数和穗粒数均较少,因此这两个高密度处理的产量均较低.综合来看,在冀东地区,适期播种条件下,小麦京冬8号以种植密度为每公顷375万～525万株为宜,此密度下茎秆质量较高,抗倒伏能力较强,产量较高.

Effect of Planting Density on Lodging-Resistance and Grain Yield of Winter Wheat in the East of Hebei Province

To understand to the effects of planting density on lodging-resistance and grain yield of winter wheat in the east of Hebei province,the experiment was conducted with four planting densities ( including 375×10⁴,525×10⁴,675×10⁴,825×10⁴plants per hectare) at the experimental station of life & science of Hebei Normal University of Science & Technology from 2011 to 2013,with the local winter wheat cultivar Jingdong 8 as material. The relevant indicators of stem quality,lodging resistance index,grain yield were investigated. The results showed that with the increase of planting density,the length of the first basal internode,ratio of basal internode to whole stem,plant height and gravity center height increased,and the diameter of basal internodes and mechanial strength of stem and lodging resistance index reduced.The stem quality was reduced significantly,and the lodging appeared under the planting density of 675×10⁴plants per hectare. With the increase of planting density,lodging occurred earlier and more serious. The higher planting density led the more PDW in early period. However,with a lot of tillers died,and stem taperred off in the treatments of large planting density along with wheat growth,which made the productivity of dry matter reduced. Therefore,the largest dry mass accumulation amount after anthesis and dry matter transfer amount appeared in the treatment of 525 ×10⁴plants per hectare at maturity stage. The most effective head number and the lightest weight per 1 000 grains appeared simultaneously in the treatment of 675×10⁴plants per hectare,and the effective head number and grain number per head were significantly less in the treatment of 825×10⁴plants per hectare. Therefore,the grain yield was significantly low in the above two treatments. The highest grain yield appeared in the treatment of 525×10⁴plants per hectare,compared with the above two treatments.However,there was no significant difference between the two treatments of lower planting densities. According to the results,in the east of Hebei province,it was suggested that the optimal planting density was 375×10⁴~525×10⁴plants per hectare under suitable sowing time.