Abstract: Through the analysis of correlation and path between agronomic characters and biological yield of summer-sowing food and fodder dual-purpose silage maize (Zea mays L.),the results of showed that the main agronomic traits that were significantly positively correlated with the biological yield of silage maize were plant height,ear height,stem diameter and number of green leaves,among which the correlation value of stem diameter (r=0.7037) was the largest.The correlation coefficient between ratio of whole plant weight to ear weight,ear weight and total fresh weight were positive but not significant.The direct path effects of each character on total fresh weight was in the order of stem diameter >ear weight >ear height >number of green leaves >plant height >ratio of whole plant weight to ear weight,and the direct effects of stem diameter and ear weight on total fresh weight were extremely significant.Stem diameter in the direct path coefficient of total fresh weight was 0.4502,which was the biggest direct positive effect.In order to obtain a higher total fresh weight,it was necessary to select the varieties with thicker stem diameter,higher plant height and ear height,more green leaves and larger ratio of whole plant weight to ear weight.Ear weight in direct path coefficient of total fresh weight was 0.4068,whose direct positive effect value was bigger,but through other characters effect value were negative,so the total fresh weight of silage maize couldnot be determined only by ear weight in character selection,but could be considered increasing the ear weight appropriately.

Key words: food and fodder dual-purpose, silage maize(Zea mays L.), agronomic characters, biological yield, correlation