密度对吉林省不同生态区玉米产量及其构成因素的影响

Effects of density on maize yield and yield components in different ecological zones of Jilin

在吉林省的2个生态类型区布置种植密度试验,重点分析密度和生态因素对玉米产量及其构成因素的影响。结果表明:1)随着密度的增加,公主岭地区千粒重逐渐下降;而在桦甸地区,随着密度的增加产量显著增加,穗粒数下降;2个地区均以8万株/hm2的产量最高,分别为12 815和11 453kg/hm2。在同一个密度水平下,公主岭地区的产量和千粒重高于桦甸地区。2)生态因素对产量和千粒重的影响较大,对单位面积穗数和穗粒数的影响较小。产量、千粒重与积温呈显著正相关,说明热量条件不足是限制玉米产量和千粒重的主要因子。尤其是灌浆中期至成熟期的积温,保证这个阶段的积温是保证产量的关键,最适日均温为24.98℃。3)在高密度条件下(8万株/hm2),桦甸地区大喇叭口期至吐丝期的日照时数较高,有利于增加单位面积穗数。

Field experiments were conducted in Gongzhuling and Huadian of Jilin Province in order to analyze the influence of ecological factors and different densities on the yield and the yield components.Five planting densities were applied 40 000,50 000,60 000,70 000 and 80 000 plant/hm2.The results were as follows：1） In Gongzhuling,grain yield and grain numbers per ear were not affected with the increase of planting density,while the 1 000-grain weight decreased significantly.In Huadian,grain yield significantly increased with the increase of planting density,while grain number per ear decreased.Both of the two areas obtained a maximum yield of 12 815 and 11 453 kg/hm2 at 80 000 plant/hm2.2） Ecological factors greatly affected the yield and 1 000-grain weight of maize,but had little effect on the number of ears per mu or grains per ear.In addition,the yield and 1 000-grain weight was significantly correlated with the accumulated temperatures.It was demonstrated that the lack of heat was the main limits to yield and 1 000-grain weight of maize.Accumulated temperature during mid-filling to maturity was critical for grain yield,and optimal daily temperature was 24.98 ℃.3） Sunshine hours during 12-leaves stage to silking in Huadian was longer than in Gongzhuling,which benefit to ears per hm2 under high density