Study On Population Structure And Photosynthetic Characteristics On Super-high-yield Maize

In this experiment, compact-type maize (Xianyu335 and Zhengdan958) and flat-type maize (Jidan35 and Jidan136 ) were selected for studying on the canopy structure, photosynthetic characteristics and yield formation in different densities, exploring the reasonable composition of canopy structure of super-high-yield, determining the best types and densities of super-high-yield. The field trials were conducted at Jinsha, Huadian city(Jilin, China) in 2008 and 2009, and were adopted split plot design, five density treatments were 1500plant/667m2, 3000plant/667m2, 4500plant/667m2, 6000plant/667m2 and 7500plant/667m2. Every plot had 14 rows of 6m long, the whole experiment arranged three repeats. The index of canopy structure and photosynthetic characteristics were evaluated at the main growth stages. And the yield were estimated in mature stage. The main results of this experiment were as follows:1 In the whole growth period Leaf Area Index(LAI) changed with the single peak curve, and the maximum was at the silking stage. LAI increased as the plant density increased, the decrease degree of LAI increased at first and then decreased as the plant density increased during the later growth stages. After silking stage LAI of Xianyu335 and Zhengdan958 were larger and decreased slower than Jidan35 and Jidan136. The plant height of each variety increased and then decreased as the plant density increased, Xinayu335 and Zhengdan958 were more higher. The stem-leaf angle of each level was decreased as the plant density increased. The stem-leaf angle of Xianyu335 and Zhengdan958 were smaller than the other varieties. The stem-leaf angle of Jidan35 and Jidan136 showed: the upper layer