Abstract: Exploring the main agronomic traits of high-yield maize can provide scientific basis for the selection of high-yield maize varieties and the breeding of new varieties. We conducted a field experiment with 76 maize varieties in the main maize production area of central Hebei Province. During the maize harvest period, we measured plant height, stem diameter, ear height, ear length, ear diameter, rows per ear, grains per row, grains per ear, 100-grain weight, bald tip length, and yield. Those main agronomic traits were further analyzed with eigenvalue analysis, correlation analysis, and boundary line analysis. The results were as follows: 1) There were significant genotype differences in agronomic traits and yield among the 76 examined maize varieties. There was a difference of 6133.2 kg·hm^-2 between the highest and lowest yields, with a variation coefficient of 12.9%. 2) Seven variables, including ear length, ear diameter, grains per row, grains per ear, 100-grain weight, plant height, and ear height, were significantly correlated with each other. All the variables showed a significant positive correlation with yield. 3) Boundary line analysis showed that these seven agronomic traits had a parabolic relationship with boundary yield, and their contribution to yield was in the order of grains per ear>100-grain weight>grains per row>ear length>ear height>ear diameter>plant height. The suitable range for agronomic traits with a target yield of 13000 kg·hm^-2 was as follows: ear length of 16.7-18.4 cm, ear diameter of 3.7-4.8 cm, grains per row of 29.7-38.1, grains per ear of 542.9-683.0, 100-grain weight of 32.9-43.5 g, plant height of 242.4-320.7 cm, and ear height of 81.3-120.4 cm. When screening and breeding high-yield maize varieties in the central Hebei Province, special attention should be paid to these seven agronomic traits, especially grains per ear and 100-grain weight.

Key words: maize variety, yield, agronomic trait, correlation analysis, boundary line analysis