Abstract: In order to make clear the effects of plant growth regulators(PGRs) on stalk growth redundancy and yield formation of summer maize,field experiment was conducted at the Xinji experimental station of Agricultural University of Hebei during 2014-2015.The effects of two PGRs(Duntianbao and Xishibao) on leaf photosynthetic rate,dry matter accumulation and partitioning,stalk characters and grain yield were studied using maize hybrid Liyu 16 as material under planting densities of 56 300,75 000 plants/ha.The results showed that maize growth and development and yield were effected by different degree with the PGRs treatment. The effects were more significant under high density. The 1000-grain weight and yield of maize of Duntianbao treatment under high density could be increased by 8.28%, 17.59%, respectively; it could be increased by 5.40%, 23.15%, respectively for Xishibao. The ear-leaf photosynthetic rate was significantly increased for the two PGRs.At dough stage,the ear-leaf photosynthetic rate of Duntianbao and Xishibao under low density was increased by 35.72% and 18.08%,respectively,while it was increased by 36.11% and 30.91% under high density.The length of basal inter-nodes was decreased,while it thickness and puncture resistance were increased,so the lodging resistance ability was enhanced.It could be deduced from the study that stalk redundancy was exist under high planting density and it could be decreased by proper PGRs,thus maize yield could be improved.At the same time,a new idea for studying the improvement of PGRs on maize yield from the view of redundancy control in the future was supplied.

Key words: Summer maize, Stalk redundancy, Planting density, Chemical regulation, Yield

CLC Number: 

• S513.01