Objective The heat resistance identification test of sweet corn varieties was carried out in order to screen out high quality heat-resistant sweet corn varieties suitable for summer sowing in south China.

Method The experiment took Yuetian 39 as the control variety, and eight new sweet corn varieties including Yuetian 38 as the experimental materials. The summer growth period was all under the condition of high temperature and humidity. Comprehensive evaluation on heat resistance of different varieties was conducted through single factor analysis and correlation analysis, and the sweet corn varieties with good heat resistance were screened out.

Result The agronomic traits highly correlated with the yield of sweet corn were ear diameter, total grains number, seed setting rate and ear height. Among them, the high quality new varieties Yuetian 40 and Yuetian 59 cultivated by heat resistant materials had better comprehensive performance, and the fresh spike yields reached 16 840.3 kg/hm² and 15 264.4 kg/hm², respectively, which were 19.1% and 8.0% higher than the control Yuetian 39, and the net spike yield reached 13 179.3 kg/hm2 and 11 700.9 kg/hm2, respectively, which were 37.4% and 22.0% higher than the control, suitable for summer planting in south China.

Conclusion Among the 8 sweet corn varieties, Yuetian 40 and Yuetian 59 had better comprehensive agronomic traits than the control variety Yuetian 39, showing better heat resistance, suitable for summer planting in Guangdong and suitable for large-scale promotion and demonstration.