Analysis of Agronomic Characters and Yield for Different Periods Maize Hybrids in China

Twenty maize hybrids and thirty-two parents in different periods utilized widely on maize production in China were chose as the materials in the study. Changing trend of hybrids and inbred lines yield, correlation analysis between parent yield and hybrid yield, affecting of agronomic characters to yield were made by split plot design. The results indicated that yield of hybrids and midparents increased gradually with varieties replacement, parents yield and hybrids yield was significant positive relationship, correlation and path analysis of agricultural characters indicated that ear diameter, ear weight, kernel length, growth period and 100-kernel weight were significant positive relationship with yield at 0.01 or 0.05 level, angle of leaf just above the node bearing the uppermost ear, tassel branch number were negative significant relationship with yield at 0.05 level, the principal of agronomic characters on yield increase were ear weight, growth period, 100-kernel weight, shelling percentage and plant density. It could draw the conclusion that the contribution of maize yield increase owed to the increase of parents yield, plant density, optimization of plant type and ear characters.