Effects of Concave Canopy Structure Shaped with Ethephon on Yield and Its Correlated Characters in Summer Maize

Canopy structure has strong effects on grain yield in maize(Zea mays L.). In this paper, the effects of different canopy structure shaped on growth and development and yield charaters were studied in the compact maize Xundan20 to exprore the potential of improving maize population yield, by various Ethephon sprayed treatment at jointing. The results showed that the treatment of spraying Ethephon at intervals of two lines could shape a concave canopy, which showed a higher yield than the shorter canopy (spraying Ethephon at all lines) and the common canopy (control) at the high planting density. The mechanism of increasing production for concave canopy was that it could raise the edge effect in population and improve the light intensity on the lower leaves. It was considered that shaping the concave canopy structure by aitificial measures such as chemical control at intervals and belt-shape intercrop of tall and short cultivars could be an important way to further improve maize population yield.