高密植对不同类型玉米品种茎秆抗倒特性及产量的影响

以增密增产潜力较大的先玉335、内单314、郑单958和稀植大穗品种沈单16、四单19、浚单20、内单205、科河8号为试验材料,在7.50×104、9.75×104、12.00×104株/hm23种高密植条件下,研究高密植对不同类型玉米品种的茎秆抗倒伏特性和产量性状的影响。结果表明,在高密植条件下,茎秆周长、茎单位长度干重与茎秆力学特征均随种植密度的增加而逐渐减小,且不同类型玉米品种间的茎单位长度干重与力学特征差异显著,可作为鉴别抗倒能力的指标;高密植致使千粒重、穗粒数和结穗率降低,耐密品种能够高产的主要原因是具有较高的千粒重与结穗率,较高的结穗率是确保高密植条件下高产的主要因素。

Stalks Lodging-resistance Characteristics and Yield Traits among Different Maize Varieties under High Close Planting

The stem lodging-resistant characteristics and yield traits were investigated among the varieties of Xianyu335, Neidan314, Zhengdan958, Shendan16, Xundan20, Neidan205 and Kehe8 under the densities of 75 000, 97 500 and 120 000 plants per hectare. The result showed that stem circumference, stem dry matter weight per unit of length and stem mechanics characteristic vary under different densities. With density increased, the indexes above decreased gradually. The stem dry matter weight per unit of length and stem mechanics characteristic can be regarded as the lodging-resistant characteristic indexes. The 1 000-kernals weight, number of grain ear and ear rate were decreased under high density. The higher 1 000-kernals weight and ear rate, the more yield of the density tolerant varieties. The higher ear rate is the main factor to increase population yield.