Impact of recent breeding history on the competitiveness of Chinese maize hybrids

•Maize hybrids released in different eras varied in their competitiveness.•The competitiveness of maize hybrids was reduced by breeding.•We tested Donald’s concept of communal ideotype, wherein modern high yield hybrids should not perform well in competition with other genotypes.•Variation in architectural plant traits among hybrids was not completely consistent with their variation in competitiveness.